A **Nordita Scientific Program** is an extended workshop where a limited number of scientists work together on specific topics for a period of up to 4 weeks. Nordita also organizes **Workshops, Conferences and Meetings**, ranging from a few days up to a week.

Program

4—29 September 2023

*Coordinators:* Jay Armas, Cristina Marchetti, Leo Radzihovsky, Amos Yarom

Hydrodynamics has a universal character spanning various energy scales: it emerges as an effective description of black holes, accretion disks at astrophysical scales, plasmas in fusion reactors, electron ﬂows in quantum matter or of the activity on cellular membranes. This program will bring together experimental and theoretical physicists working on different aspects of hydrodynamics in order to share methods for solving problems in ﬂuid dynamics and fostering new collaborations.

Some of the most profound open problems about the physics of non-topological Quantum field theories – especially at strong coupling, beyond the reach of conventional techniques – are newly accessible thanks to recent developments in topological quantum field theory (TQFT). This insight comes with a dramatic evolution of the notion of symmetries in QFT: symmetries can be characterized via topological defects of various codimensions whose multidimensional fusion generalizes wildly the notion of groups to what are called categorical symmetries.

Program

31 July — 11 August 2023

*Coordinators:* Andy O'Bannon, Charlotte Kristjansen, Christopher Herzog, Konstantin Zarembo, Matthew Buican

Boundaries, impurities, and defects play a ubiquitous role in understanding the universal behavior of strongly-coupled systems, from topological states of matter to confining gauge theories. The program will focus on new developments in this area, including holographic duality, new phases of boundary QFT and RG flows, anomalies and c-theorems, supersymmetric localization, bootstrap methods and integrability.

Program

26 June — 21 July 2023

*Coordinators:* Alessandra Buonanno, Andrea Puhm, Daniel Baumann, Henrik Johansson, John Joseph Carrasco, Oliver Schlotterer, Paolo Di Vecchia, Zvi Bern

This Nordita program is devoted to amplitudes- and QFT-inspired analytic methods for gravity at all scales. The topics covered will include: recent progress for gravitational amplitudes, new perturbative/effective formalisms, and relations between gravity and gauge theory. Higher-order calculations for: post-Newtonian/Minkowskian and self-force corrections to the gravitational potential/wave emission, cosmological correlators and ultraviolet physics probing quantum gravity, and applications to string theory. Challenges of incorporating spin and tidal effects in general relativity, and scattering amplitudes for Kerr black holes. Flat space holography in the form of celestial amplitudes, asymptotic symmetries and gravitational memory.

Program

29 May — 23 June 2023

*Coordinators:* Ganna Rozhnova, Igor Rouzine, Tom Britton

This program will focus on analytical and computational modelling approaches in infectious disease dynamics and evolutionary dynamics of viruses - the two theoretical topics that have traditionally been addressed in separation.

Program

2—26 May 2023

*Coordinators:* Claudia Cenedese, Luca Brandt, Ekaterina Ezhova, Shervin Bagheri, Frida Bender, Geert Brethouwer

To mitigate climate changes and propose adaptation strategies we need to better understand a wide range of flow phenomena in the atmosphere and the ocean, spanning length scales from micrometres to thousands of kilometres, and time scales from milliseconds to months or years. Investigating the influence of small scales processes to the large scale one and vice versa is a great challenge which can not be tackled by a single discipline or tool, hence the need of this workshop to bring together people from different disciplines using a variety of tools, e.g. numerical modelling, laboratory experiments, field data, satellite images, analytical methods.

Program

3—28 April 2023

*Coordinators:* Anvar Shukurov, François Boulange, Frederick Gent, Jennifer West, Jörg R. Hörandel, Marijke Haverkorn, Tess Jaffe

The goal of the program is to achieve tangible progress in our understanding of the structure and origin of the Milky Way's magnetic field, to pave the way for further progress in this direction, and to address a range of fundamental questions in other areas of galactic astrophysics that have magnetic fields and cosmic rays at their core. Specific questions include: What are the properties of magnetohydrodynamic turbulence in the interstellar medium? What can we learn from the observations of other galaxies (and contribute to) galaxy formation theory? What is the interplay between cosmic structure, magnetic fields and the origin and propagation of extragalactic cosmic rays?

Program

20—31 March 2023

*Coordinators:* Axel Brandenburg, Bernhard Mehlig, Gunilla Svensson

How particles or droplets can grow in a turbulent environment is of great current interest in many fields, in astrophysics, cloud microphysics, in biology, and in the engineering sciences. Yet the microscopic mechanisms determining this growth are far from understood, and the challenge is now to understand how and under which circumstances these mechanisms may lead to or prevent particle growth in turbulence. The program is aimed at scientists interested in the dynamics and the growth particles in turbulence, applications in the atmospheric sciences, astrophysics and engineering, or the mathematical analysis of these phenomena.

Program

25 July — 19 August 2022

*Coordinators:* Amin Doostmohammadi, Chantal Valeriani, Gareth Alexander, Julia Yeomans, Miha Ravnik, Tapio Ala-Nissila

Living systems exhibit a fascinating range of dynamic, non-equilibrium behaviours including self-organisation, collective motion, growth and development. Many traditional, and new, concepts in soft matter physics can be applied to gain physical understanding of living matter. This interaction between soft matter physics and living systems has the potential for transformative insights into cell biology, tissue dynamics and driven non-equilibrium behaviour in general, as well as suggesting design principles for new artificial materials and machines that are capable of self-propulsion, self-healing and self-organisation.

Program

16 June — 2 July 2022

*Coordinators:* Alexander Krikun, Blaise Goutéraux, Debanjan Chowdhury, Ipsita Mandal, Peter Abbamonte

Strongly correlated quantum matter is one of the most facinating subjects in modern Physics. Modern experiments keep on unraveling new puzzling phenomena which cannot be addressed with conventional approaches of condensed matter physics. The program will focus on recent experimental developments on strongly-correlated systems such as strange/bad metals and twisted Graphene/Moiré systems. Many new theoretical techniques have emerged in the past decade or so from a fruitful and intense dialogue between the condensed matter and high-energy/string theory communities. As such, the participants to the program will hail from a variety of backgrounds in experimental and theoretical condensed matter as well as high-energy theory.

Program

16 May — 7 June 2022

*Coordinators:* Axel Brandenburg, Maarit Käpylä, Matthias Rheinhardt

Dynamo theory explains why the plasma in our universe is magnetized. As we now know, astrophysical turbulence without magnetic fields does not exist. This has dramatic consequences, especially when the magnetic Prandtl number is very different from unity. Examples include the interstellar medium and especially clusters of galaxies. There we also reach the limits of validity of magnetohydrodynamics and thus need to worry about the correct microphysical description. In the Sun, a large-scale dynamo is most likely operational within the bulk of the convection zone, but this situation drastically changes as the surface and atmosphere are reached. Simulating these aspects correctly on the computer requires special care, which we are only now beginning to appreciate. The goal is to use Nordita's inhouse expertise in the field of dynamo theory to draw together experts from within the Nordic countries and elsewhere to prepare the way for new work.

Program

2—13 May 2022

*Coordinators:* Astrid de Wijn, Bart Cleuren, Ralf Eichhorn, Supriya Krishnamurthy

It has been a vision from the early days of statistical mechanics to develop a theoretical description for small non-equilibrium systems that is comparably powerful and universal as is equilibrium statistical physics. In recent years a number of new ideas and approaches in this direction, such as large-deviation theory, non-equilibrium phase transitions, and stochastic thermodynamics, have led to the first discoveries of exact relations characterizing universal properties of small non-equilibrium systems, which are valid beyond linear response.

Program

18—29 April 2022

*Coordinators:* David Milstead, Elin Bergeås Kuutmann, Gabriele Ferretti, Jörgen Sjölin, Rikard Enberg, Sara Strandberg

This program, sponsored by Nordita with the additional support of the Knut and Alice Wallenberg Foundation, aims at taking stock of the outcomes of the recent searches for physics beyond the Standard Model at LHC and elsewhere and quantifying the extent to which they constrain models attempting to restore naturalness. The expected sensitivity from future high precision running at the LHC and of planned non-collider experiments will also be addressed.

Program

4—15 April 2022

*Coordinators:* Christian Schneider, Habib Rostami, Oleksandr Kyriienko, Philip Hofmann

The program will bring together leaders in research areas of light-matter interaction, two-dimensional materials (2DMs), and quantum applications, thus merging these rapidly developing fields. The following topics will be covered: Nonlinear optical response of 2D materials, Nonlinear electronic transport in 2D materials, Time-resolved photoelectron spectroscopy, Exciton and Trion quantum physics in TMDs, and Polariton quantum physics in TMDs

Program

2—27 March 2020

*Coordinators:* Hideyuki Hotta, Markus Roth, Petri Käpylä

Understanding stellar convection is of crucial importance to many fields of stellar astrophysics. For example, the generation and maintenance of differential rotation and large-scale magnetic fields in stars rely on turbulent convection. However, mounting evidence suggests that our understanding of stellar convection is much more incomplete than previously thought. We bring together experts in three-dimensional convection simulations, helio- and asteroseismology, and theoreticians working on replacing the mixing length concept to present the latest developments and to address open problems in the field.

Gravitational waves promise a new window into the highest-energy events in the evolution of the universe. The recent LIGO/Virgo detections of gravitational waves from the mergers of binary black holes and binary neutron stars and have ignited interest in the future direction of gravitational wave astronomy. A space-based laser interferometer, pioneered by NASA's LISA concept and the European Space Agency's eLISA program and ESA's recent spectacularly successful LISA Pathfinder mission, would enable direct detection of gravitational waves in the milliHertz range. A lower frequency range would allow detection of supermassive black hole mergers, tracing the galaxy merger history and serving as cosmic sirens to probe the universe's expansion history, as well as precursors for the LIGO sources. A space-based detector would also be sensitive to stochastic gravitational wave backgrounds produced by unknown physics operating in the very early universe, including an electroweak phase transition. This Nordita program will bring scientists together to engage in an effort to characterize and detect sources contributing to the gravitational wave background from the early universe, and the implications for new physics at the TeV scale and beyond.

Recent advances in the band theory of crystalline materials have singled out topology as a key ingredient in the modern classification of matter, with major impact on measurable electronic properties. Topological band theory has also grown into an emerging paradigm in many areas of physics, and is now used to characterize metamaterials, including photonic, atomic, acoustic, and elastic systems, in both the quantum and classical regimes. As our understanding of topology in physics widens, the incorporation of out-of-equilibrium phenomena is gaining in importance.

Growing amount of molecular biological data combined with current advances in modeling of complex systems provide unprecedented opportunities to understand biological evolution in a quantitative way. A quantitative description of an evolving system is the first step towards prediction and control, and it opens new exciting directions for highly interdisciplinary research. The central questions are: (i) to what degree we can predict the outcome of biological evolution, (ii) what features of the system are predictable and (iii) which features confer predictive value for a quantitative description of the system. This program brings together theoretical and experimental physicists, experimental biologists with an interest in quantitative modelling and mathematicians with interest in biological systems.

This Nordita Program is devoted to theoretical and observational studies of the interstellar medium of galaxies across cosmic time, and to their implications in shaping future line-intensity mapping experiments which have recently generated a tremendous interest in the Community of astrophysicists and cosmologists. The program is particularly timely because the advent of new facilities, such as ALMA full array, JWST (launch spring 2019), and E-ELT (2024), will provide a wealth of high resolution multi-wavelength spectroscopic data on the ISM of galaxies across cosmic time. Moreover, the program will bring together experts from different areas as we aim gathering astrophysicists, working on galactic and extragalactic observation, theoreticians devising simulations, astrochemists, and cosmologists interested in the large scale structure of the Universe. The program has been conceived with a bottom-up structure that, from ~pc scales, relevant for star formation, will zoom-out up to ~Mpc scales relevant for intensity mapping experiments.

Physical systems look different when observed at different resolutions: what appears as a continuum liquid to the naked eye becomes a cluster of jiggling atoms when observed at the resolution of an electron microscope. Effective field theory provides a description of physics in terms of degrees of freedom appropriate to a given resolution. Over the last couple of decades, physicists have developed effective field theory tools which, to a large extent, unify fields as diverse as atomic and condensed-matter physics, particle and nuclear physics, and cosmology. The ensuing interaction between different branches of physics has never been as fruitful as it is now. The aim of this program is to give a new impulse to a further development of this exciting interdisciplinary field. We bring together leading practitioners working on effective theories of quantum phases of matter across several branches of physics. Our goal is to map out important open problems with broad relevance and look for new directions towards their solution, to reinvigorate existing collaborations and foster new connections.

Quantum Information Science is a major frontier of modern science and technology, exploring physical situations that are classically impossible. An important technological application, already available today, is secure quantum key distribution realized by spatially separated entangled quantum states. This program will be centered around new fundamental physical questions that will emerge from successful current and future quantum technologies. The focus will be on effects and phenomena that appear already in low-dimensional quantum systems, and which are (or may soon be) experimentally realized.

Magnetic helicity is a conserved quantity in ideal MHD and is also a topological invariant. Due to these properties, it plays special roles for the operation of the global solar dynamo, and in the release of solar eruptive events, but both of these related processes remain poorly understood. On both themes, theoretical models would benefit from being validated and constrained with observational data, and the increasing amounts of observational data could be more efficiently used as basis to improve the models. The abundant observational data pouring in from various sources poses its own challenges and sometimes cross-calibrations are lacking. This program will bring together solar observers and dynamo theorists to work on these topics. We aim to obtain crucial new knowledge on the operation of the global solar dynamo itself, but also how it drives eruptive events which then are observed as space weather.

This program is devoted to the discussion of the latest theoretical and experimental advances related to chiral magnetic phenomena and their relevance for plasma physics, particle physics, condensed matter physics, astrophysics and cosmology. Included topics: Chiral magnetohydrodynamics (MHD), including theory of laminar and turbulent dynamos in chiral MHD and impact of chiral magnetic phenomena on waves in plasma; Direct numerical simulations of laminar and turbulent dynamos in chiral magnetohydrodynamics; Astrophysical and cosmological applications of chiral MHD: the early Universe, neutron stars, quark-gluon plasmas; Applications of chiral MHD to high-energy heavy ion collisions at RHIC and LHC; New materials with pseudo-relativistic electrons and chiral magnetic effect.

The program explores recent developments in describing the dynamics of strongly-coupled field theories using the notion of fundamental, quantum bounds on transport, and their interplay with quantum chaos. By bringing together international leaders in condensed matter and high-energy physics, we aim at enhancing our current understanding by combining experimental results and the various theoretical, non-perturbative approaches to these problems. Participants will include experts in thermoelectric transport experiments, hydrodynamics, gauge/gravity duality, condensed matter and conformal field theory.

Almost a century ago Einstein’s seminal paper 'Cosmological Considerations in the General Theory of Relativity' (2 August 1917) proposed a game changing addition to his theory of general relativity: Lambda, the cosmological constant. Since then, and in particular from the remarkable experimental data gathered during the last two decades, the cosmological constant has gone from a theoretical sideline to a central feature of research in cosmology and quantum gravity, including the effective Λ of inflation, the observed Λ of the late time acceleration of our universe, and the negative Λ of the gauge/gravity correspondence in string theory. Theoreticians and philosophers have been fascinated and aggravated by 'the Lambda Problem' for a century. The advent of precision cosmology has made this an issue of practical relevance, and this workshop will be productive through critiquing and advancing theoretical approaches within the constraints of observations.

Since the discovery of topological insulators about a decade ago, the field has been focused on non-interacting gapped fermionic states, classified within the so-called 'ten-fold way periodic table'. However, new topological states of matter not captured within this classification have recently been theoretically proposed and experimentally discovered. These include topological crystalline insulators, Weyl semimetals, but also classical topological states in mechanical metamaterials. Given these developments it is clear that the study of topological matter is entering a new period where the themes going 'beyond the ten-fold way' take the center stage. In this program, we bring together experimentalists and theorists to review the current status of this burgeoning field, identify the crucial areas where progress can be made, and foster collaborations and partnerships to vigorously pursue these goals.

The program will bring together a group of theoretical physicists, mathematicians, experimental biologists, and experimental biophysicists, to study the mechanisms by which (i) protein assemblies, such as biopolymers, exert forces in cells, (ii) protein assembly dynamics in cells are regulated by forces, and (iii) the dynamics of force-generating assemblies are controlled by signaling pathways. The program will enhance the formation of collaborative links between experiment and theory, as well as those between theorists using different methodologies. It will also clarify the links between apparently disparate, but related phenomena by bringing in individuals with a broad range of backgrounds. Finally, it will enhance the development of the mechanobiology community in the Nordic countries.

The program will bring together theoretical physicists and mathematicians working in the seemingly different areas where exactly solvable or integrable models make pronounced appearance: integrability in gauge theories, stochastic processes and non-equilibrium dynamics, quantum quenches, chaotic behaviour in statistical systems, matrix models for topological strings and N=2 gauge theories based on localization, symmetric polynomials, Hall and cluster algebras.

Numerous systems including deformation and fracture of materials, dynamics of domain walls in ferromagnets, and earthquakes respond to slow and smooth external driving by exhibiting intermittent and bursty dynamics, or 'crackling noise', consisting of a sequence of events with a broad size distribution. A major challenge we aim to address within this program is that in many cases, the relevant empirical and experimental phenomena remain unexplained by theory. To this end, we plan to bring together experts of various fields where crackling noise is observed, including contributions from theory, numerical simulations and experiment, to present an overview of the current developments, and to discuss open problems of the field.

Stochastic thermodynamics is a recently established discipline of statistical physics. It aims to apply and extend thermodynamic principles to the non equilibrium regime. In particular, it provides an adequate framework to investigate the behaviour of small systems. The salient property of stochastic thermodynamics is the incorporation of fluctuations, which are prominent on that scale. In combination with the constraints put forth by macroscopic thermodynamics, a number of important fundamental results were established, e.g. the fluctuation theorems. Stochastic thermodynamics is by now a rapidly evolving field, with an increasing range of applications. The aim of this program to discuss the latest developments and open problems in Stochastic Thermodynamics.

Topological phases play an important role in condensed matter physics for understanding quantum effects like topological insulators and the quantum Hall effect. At the same time, cold atoms and ions have matured as a testbed to study complex quantum systems and are now used to generate, visualize and understand topological quantum states and phases. This program will bring together researchers from condensed matter and atomic physics, to share their knowledge how to describe and investigate topological quantum systems and to inspire collaborations between researchers of the two fields.

*What is the expansion history of the Universe? What are dark energy and dark matter? Is Einstein’s theory of gravity valid on cosmological scales? What generated the initial perturbations that grew into stars and galaxies?* We are gradually developing the observational and theoretical prowess to tackle the most fundamental unknowns of our Universe, the nature of dark matter and dark energy, and to shed light on the dark ages spanning the dawn of time to the birth of the first star. Through observations of the Cosmic Microwave Background and Large Scale Structure we are unravelling this cosmic puzzle while constraining the inflationary physics that we believe is responsible for generating the primordial perturbations, the seeds of our universe. By complementing these studies with information from cosmological messengers, such as neutrinos and gravitational waves, we link our cosmological understanding to fundamental physics. The challenge for further progress lies at the intersection of these thrusts; strong interactions and collaborations between the theory and observations are required to answer key questions of modern day cosmology.

Massive stars, almost always found in pairs, evolve and end their lives as extreme-gravity compact objects - white dwarfs, neutron stars and black holes. Binary stellar interactions and gravitational radiation drive these two objects together resulting in their mergers. Such mergers are widely accepted to give rise to a host of the most energetic transient events known in the Universe. By critically assessing binary stellar interactions and evolution, this multidisciplinary program will bring together theorists, computational astrophysicists, observers, and instrumentalists for a period of three weeks. Our aim is to systematically connect the binary progenitors through the complex merger physics to the myriad of observed and predicted cosmic transient events.

Phase transitions occur constantly in the interstellar medium and to a large degree define star and planet formation. The transition from atomic to molecular gas sets the initial conditions for star formation, while the formation and destruction mechanisms of dust and other solids is the basis for understanding the origins of planets. This program aims to bring together experts in ISM dynamics, planet formation, exoplanet atmosphere, and planetary ices, from both modeling and observations to study this problem in detail.

Dark Matter (DM) binds our galaxy together and is at the heart of modern cosmology. The current Lambda Cold DM paradigm has had great success on large scales, but a detailed understanding of the distribution of DM on smaller scales is still lacking where new data from Gaia could challenge the CDM scenario or rule out competing models such as warm dark matter. Gaia will measure the proper motion and distances of on the order of a billion stars in the Milky Way's disk, bulge and halo, as well as in a few individual Milky Way satellites. The focus of the workshop is to bring theorists (particle physicists and astrophysicists), modelers, and observers together in order to discuss ideas, methods, and modeling to focus our understanding of the local universe revealed by Gaia at a critical time when the first data from Gaia will become available.

Turbulent combustion is not only a part of our daily life (e.g. in combustion engines that power road vehicles, airplanes, space vehicles and ships, as well as in power plants and numerous industrial sectors), but also it is the key process in supernovae explosions and thermo-nuclear fusion. Turbulence itself is a challenging research area and over the past few decades a significant development in experiments and high fidelity modeling has been made. Combustion is a multi-scale physico-chemical process involving reactions with a range of time scales and when coupled with turbulence they occur also in different spatial locations. Depending on the mixture composition, temperature, pressure and flow conditions rich combustion phenomena can occur: ignition, quenching, deflagration and detonation wave propagation, formation of pollutants, supernovae explosion, etc.

This Nordita Program will develop two interrelated themes to provide new insights into the underlying holographic structure of space-time and the quantum nature of black holes. We will focus on the interplay between quantum entanglement, entropy and the emergence of space-time from quantum field theory in the context of holographic dualities. A parallel theme involves extending the notion of holographic duality to more general classes of space-times. Widening the scope of the holographic paradigm will open up new avenues for applied holography and may shed light on some deep puzzles in quantum cosmology. The program aims at bringing together experts in this exciting research field and introduce PhD students and younger researchers to these developments.

Modern condensed matter systems of interest, including those which display the highest superconducting transition temperatures, tend to exhibit a complex interplay of many-body ordering tendencies with ensuing multicomponent field theories. Understanding the microscopic origin and the phenomenology of such interplay has been among the most active frontiers of research in recent years. The goal of the workshop is to bring together experts working on various aspects of the field to share their latest development and spark future collaborations. The workshop will cover a wide range of topics such as: superconductivity in iron-pnictides, cuprates, and in materials without inversion symmetry, as well as other systems with unconventional pairing symmetry.

Scattering amplitudes in relativistic quantum theories possess a multitude of remarkable hidden structures and correspondences. They are of vital importance for high-precision comparisons of theory and experiment at the LHC, yet they also have the promise of revealing fundamentally new approaches to quantum field theory and of exposing interrelations that unify gauge theories, gravity, and string theory. This program will provide a meeting ground to communicate the current themes and recent progress in various areas of theoretical physics touched by scattering amplitudes. This includes N=4 SYM, higher-loop QCD, perturbative gravity, string amplitudes, polylogarithms, Grassmannians and the amplituhedron, soft theorems, twistor strings, color-kinematics duality and double-copy properties of gravity, supergravity UV behavior, and more.

Quantum field theoretical concepts are an essential tool for the understanding of a wide range of problems in condensed matter theory including the theory of quantum phase transitions, the quantum Hall effects, and frustrated spin systems. While field theories provide an effective description and capture the universal features, they cannot usually be directly related to microscopic models. Here numerical tools are of great importance to tackle quantum many-body problems starting from microscopic Hamiltonians. Over the past decades, several new numerical tools have been developed, including tensor product state based methods, multi-scale entanglement renormalization group methods and new quantum Monte Carlo methods.

The holographic duality has provided new insights into the physics of strongly-coupled systems by bridging together different subjects that before were thought to be completely unrelated, such as hydrodynamics and physics of black holes, string theory and strongly-coupled phenomena in condensed-matter physics, integrable systems and and non-perturbative behavior of gauge fields. Symmetries have played an important role in these developments and have led to development of new non-perturbative methods based for example on integrability, bootstrap and localization. The aim of the program is to discuss new developments in dualities and holography, with focus on gauge/string dualities, integrability, symmetries in string theory, supersymmetric localization, bootstrap methods, applications of holography in QCD and condensed-matter systems.

"Stochastic Thermodynamics" represents an exciting new research direction in statistical physics, which explores fundamental aspects of non-equilibrium processes. The common idea is to adapt and generalize concepts from equilibrium thermodynamics to the non-equilibrium realm, typically on the level of single particle trajectories monitored over the entire system evolution. The program intends to gather the world-leading experts to explore the possibilities of applying the tools of Stochastic Thermodynamics to open questions in biological systems, mainly on the cellular and molecular level.

A major direction of research in contemporary condensed matter physics is the effort to design materials with specific functionality by utilizing the unique properties of interfaces between materials of different types. The prospect of using two-dimensional interfaces between two-dimensional layers at the nanoscale provides many potential avenues for tailoring materials. The program brings together world leaders in the fields of superconductivity and Dirac materials and young researchers from the Nordic region who can learn from them.

Magnetic reconnection is a fundamental multiscale plasma process responsible for plasma transport, plasma heating and acceleration of energetic particles in many astrophysical environments, ranging from planetary magnetospheres and solar wind to solar flares, accretion disk corona, and other astrophysical plasmas. The major goal of this program is to increase the knowledge about the magnetic reconnection process in astrophysical plasma environments based on synergies between the studies of magnetic reconnection remotely, in situ, in numerical simulations and in laboratories.

Focus themes during this program will be: observations, observational tools, prospects; MHD in cosmology and origin of magnetic fields; and magnetized structures. There will be a conference during the second week.

The aim is to study quantum control and dynamics of few-particle systems in an active collaborative effort between experimentalists and theorists, as well as between recognized senior researchers and young investigators. The activity is motivated by recent advances in the physics of ultrafast phenomena in the femto- and attosecond time scale - a regime within reach of novel light sources. New insights into fundamental many-body physics are expected when ultrafast atomic and solid-state processes can be monitored in real time.

The cosmological constant and the physics behind dark energy that accelerates the expansion of the universe remain among the biggest mysteries in theoretical physics. An intriguing possibility is that these problems stem from extrapolating Einstein's General relativity from the Solar system to the far infrared cosmological scales. In the other extreme, at the ultraviolet regime Einstein's theory encounters notorious infinities resulting in spacetime singularities and obstacles to quantisation, which suggest new gravitational physics with possible repercussions to early universe physics. The program aims at establishing new links between fundamental physics and cosmological and astrophysical experiments from the fruitful interface of extended theories of gravity.

Water is ubiquitous and a prerequisite to life as we know it, yet the fundamental origin in terms of structure and dynamics of its many anomalous properties is still under debate. No simulation model is currently able to reproduce these properties throughout the phase diagram. Experimental techniques, such as x-ray spectroscopies and x-ray and neutron scattering, femtosecond pump-probe and free-electron laser experiments in "no man’s land", provide data that stimulate new theory developments. This program brings together experimentalists and theoreticians in strong synergy to advance towards a unified picture of water.

Advanced theoretical methods play a central role in answering the key questions of many-body physics. We intend to discuss and compare such methods as are being applied at present in nuclear physics, condensed matter, cold atoms and quantum chemistry. The computation techniques required to achieve an understanding of existing experimental data and in predicting with high reliability new properties and processes seem at present to be dispersed in the various fields.

Experimental research on engineered quantum states and devices is progressing rapidly, providing special opportunities and challenges for the theorist. While the basic motivation draws from the wish to understand the intriguing coherence and correlation effects often featured, the prospects to use them for processing and storing quantum information has given the field an additional boost. The program aims at offering an interdisciplinary forum to further interactions among theorists working in different subfields of quantum engineered systems.

In a frustrated system, competition between interactions hinders the tendency towards forming an ordered state, allowing for the emergence of new physical phenomena. This programme will bring together experts in the field of frustrated and critical magnetism as well as younger researchers, to discuss recent developments, explore connections between different areas of research, and generate new ideas.

The question of the dynamics of particles in flows has a wide range of applications. Examples are the dispersion of pollutants in the atmosphere, fuel injection in a car engine, rain formation in clouds, and planet formation in circumstellar accretion disks. These examples have in common that the fundamental processes (collisions, coalescence, or breakup of particles) are determined by similar microscopic equations.

The nature of Dark Matter is one of the most important outstanding problems in modern physics. Many Dark Matter models exhibit high dimensional parameter spaces with many degeneracies and considerable expected backgrounds, and therefore a combination of all experimental data available will likely be necessary to arrive at robust conclusions regarding the nature of dark matter. The aim of the program is to bring together experimentalists, phenomenologists and theorists in order to discuss ideas, methods and models for interpreting the vast amount of data available.

The focus of this program is the theory and phenomenology of neutrino physics and the role of neutrinos in astrophysics and cosmology. Important issues include extended versions of the Standard Model of particle physics including massive neutrinos, using neutrinos for probing astrophysical environments, and confronting theories with measurements. We intend the program to be a workshop in the real sense of the word, with informal discussion meetings and ample opportunities for research and discussion of common projects.

This program is about the Ly α transition in Hydrogen and its astrophysical applications. Young stellar populations are dominated by massive, hot and short-lived stars that ionize their surroundings, which is hence a powerful, but complicated, probe of star forming and high redshift galaxies. This programs aims to bring together experts in modeling Ly α radiative transfer and galaxy formation, and observations of Ly α in local galaxies and the distant universe.

Superconductivity has been of central scientific interest for more than a century, and yet the progress to date has been largely empirical: despite the tremendous progress in many-body theory there is as yet no general set of rules to predict and “design” new kinds of superconductors. With the rapidly growing list of new superconductors we feel it is time to have a high level workshop, bringing together theorists and experimentalists and focusing on the established facts and challenges in understanding the fundamental properties and basic mechanisms of superconductivity.

The 14 TeV LHC will look further above the electroweak scale, but where do we go beyond that to improve our understanding of the fundamental constituents of the Universe? Should we look to the results of a high-luminosity SLHC or a higher energy VLHC, do we need a precision linear collider at ILC or CLIC energies, are neutrino or flavour experiments essential to move forward, what can we learn from astrophysics?

This programme brings together astrophysical theoreticians and simulators interested in radiative feedback, specifically the dynamical effects of radiative heating of dense gaseous structures, a process known as photo-evaporation, which occurs in regions of intense star formation, in the dense planet forming discs around young stars, in massive planets orbiting close to their parent star and even in the earliest phases of galaxy formation in the Universe. As part of the programme a 5-day workshop will address the latest observational and theoretical results.

Stability and transition of flows belong to fundamental issues in the field of fluid mechanics. Predicting flow structures and characteristics requires deep understanding of the different routes of transition. Further, similarities between the fluid behavior (instabilities) and different phenomena within the field of astrophysics give an opportunity to explain some of astrophysical phenomena based on the stability characteristics of canonical shear flows.

The goal of the programme is to advance our understanding of the physical processes generating differential rotation in various types of stars, and the role that this effect plays for stellar magnetic activity and dynamos. The Sun is the only star for which the internal rotation profile is observationally known thanks to helioseismology – for other stars, only the surface differential rotation can be inferred from photometric or spectroscopic observations. The main goal of the program is to investigate the connection between the theories and observations and obtain better understanding of the generation and role of differential rotation for stellar magnetism.

Stochastic Thermodynamics represents an exciting new research direction in statistical physics, which explores fundamental aspects of non-equilibrium processes. The developments summarized under this term may be characterized by the common idea to adapt and generalize concepts from equilibrium thermodynamics to the non-equilibrium realm, typically on the level of single particle trajectories monitored over the entire system evolution.

During the last years, numerous achievements have been presented in the research with cold atoms, such as realizations of; various lattice models, synthetic gauge fields, orbital physics, disordered systems, non-equilibrium dynamics, dipolar gases, and many-body cavity QED. This program will gather both experamentalists and theoriticians for discussions and presentations of these topics as well as others.

Current cosmology provides a fascinating mix of a wealth of new observational data with deep conceptual problems still to be addressed. Several approaches in the general context of quantum gravity aim at a fundamental description of the relevant stages in the history of the universe, but none of them appears to be fully convincing and comparisons between different directions are difficult to draw. This workshop brings together a large set of experts, from both fundamental and phenomenological theory, in order to provide a snapshot of the current status and to focus future activities.

Holography has emerged as one of the most fascinating and powerful new concepts in modern theoretical physics. Some of the most exciting current and future advances in the field build on two amazing prospects of the AdS/CFT correspondence, and thereby the Holographic Principle. On the one hand, the AdS/CFT correspondence offers a way to study strongly coupled gauge theories, and more generally strongly coupled systems with many degrees of freedom. Conversely, it offers a way for understanding the quantum states and the quantum behavior of black holes.

Investigation of mesoscopic physics (nanometer scale systems) became a field of the intense research in last two decades, stimulated by the possibility of creation of nano-devices where the spin of the single particles could be an object of the precise manipulation and control. The workshop will seek to encourage interaction and information exchange between researchers working in the field of spin-related phenomena in various mesoscopic systems, as well as between experimentalists and theoreticians.

Topological states of matter, such as topological insulators, topological superconductors, and quantum Hall liquids, are of great recent interest, both theoretically and experimentally. The purpose of this program is to gather experts on these different types of topological states, to discuss recent developments and create an exciting atmosphere where we can come up with new ideas.

The program is dedicated to the present and future phenomenological impact of the first years of results from the Large Hadron Collider experiments at CERN. The aim is to have a very active scientific environment with theorists and experimentalists discussing the latest results and investigating future directions. During the event several topics will be discussed ranging from model building to collider phenomenology with the various links to cosmology. The 3rd week of the program is dedicated to the **Mass 2012 Conference**.

In biological systems, proper function crucially depends on dealing with large amounts of information received from a usually noisy environment. Filtering out the noise, finding structure in the incoming information, memorizing this information, and eventually using it for generating proper response are fundamental operations performed by these systems. The scale at which these operations are performed ranges from individual cells to multispecies communities.

This program focuses on the different methods for modeling the dynamics of biomolecular systems, ranging from force-field based all-atom representation of individual biomolecules to coarse-grained models for multi-component systems. In particular, the link between these 'complementary' modelling approaches, which cover distinct length and time scales, is of central interest.

There has been remarkable progress in understanding non-perturbative dynamics of gauge fields and their relationship to string theory in recent years. Many important developments have been made by using methods of exactly solvable systems. The topics will include (i) exact results in the AdS/CFT correspondence (ii) scattering amplitudes (iii) supersymmetric gauge theories (iv) Bethe ansatz and exact solvability in quantum field theory

The 4-week program will be devoted to geometrical subjects motivated by string theory, and to recent developments in string theory and related physical fields (quantum field theory) which are of strong geometrical interest. While the program will cover all areas of interaction between string theory and geometry, to provide additional focus we will emphasize particular subareas such as: the application of supersymmetry in differential geometry, generalized geometry, vertex algebras, topological field theories.

The program is centered around modern developments in non-equilibrium statistical mechanics both with respect to fundamental aspects (fluctuation theorems, entropy production, fluctuation-dissipation theorems) as well as applications (noise-induced phenomena, biophysical problems).

Thanks to novel light sources, ultrafast atomic and solid-state processes in the femto- and attosecond time scale can be monitored in real time.

Understanding the origin of solar and stellar magnetic field is one of the central problems of physics and astrophysics, and a key to understanding the cosmic magnetism, in general.

The program will try to cover what string theory has to say about physics beyond the Standard Models of both particle physics and cosmology. Topics may include but are not limited to: string effective actions, string instantons, stringy supersymmetry breaking, intersecting D-branes, generalized ﬂux compactifications, inﬂation in string theory, string-inspired MSSM-like models and dark matter in those models.

Predicting the unpredictable is a challenge that is common to various physical systems whose dynamics is governed by the equations of ﬂuid dynamics. The oldest example is weather prediction. Other examples include climate prediction, space weather forecast, and solar cycle forecast. The mathematics developed for these applications is extremely interesting and deserves more detailed understanding, so that these techniques can be used also in other areas where the application of this technique is less well developed.

The main idea is to convene key world-class researchers on complex networks and let them interact freely with the Nordic groups interested in the area. The program will be divided into four thematic areas: biological networks, general network theory, technological networks, and social networks. Many of the intended participants are interested in several of these points.

A more intense, 3-day workshop will be arranged during the middle of the program.

Research topics to be covered include: cosmological probes of dark energy, induced gravity on higher codimension surfaces and defects, K–essence, alternatives to the cosmological constant, technical naturalness as a qualified guide to new physics, vacuum structure, and stringy perspectives.

The impressively successful classical theories on phase transitions are based on the thermodynamic limit, which implies *infinitely large or small extension* on all the systems that are considered. These theories fail, however, to address many important aspects, as *finiteness in extension* is apparent in most physical systems. The question is of highly generic nature and has significance within condensed matter physics, chemistry as well as biology.

This program will run in two installments: 15 February-1 March and 12-17 December 2010.

The concept of Random Geometry covers a variety of techniques and methods. These include the physics of interfaces in statistical mechanical systems, polymer and membrane physics, the theory of propagating strings relevant in high-energy physics, the functional integral approach to quantum gravity, the description of gene regulatory networks as well as of computer networks and their use in the design of algorithms, and also random graphs and random maps with important applications in physics, combinatorics and probability theory.

Two workshops, 1-2 November and 6-7 December, and a mini-conference, 22-23 November, are planned during the program period.

The interdisciplinary field of quantum information processing and communication connects at its deepest level quantum mechanics, photonics, solid state physics, atomic physics, and electronics with computer science and information theory in order to gain features in cryptography, communication, and computing that are impossible to achieve using classical methods. Quantum information science has also revitalized the discussions about the foundations of quantum theory. This field has grown explosively and is now one of the hottest subfields of both computer science and physics.

The program will focus on frontiers in physics of quantum solids, liquids and gases (defined in a broad sense).

The program has two main themes: *Integrability in N=4 gauge theories* and *AdS/CFT duality and its applications* to eg. quark-gluon plasmas, non-relativistic CFTs, hydrodynamics, and condensed matter systems.

An objective of the program is to support interaction between the two main themes. It is anticipated that specialists from each group will be simultaneously present, allowing for the exchange of new ideas between the two groups.

The 2010 conference on Integrability in Gauge and String Theories (IGST2010) will be held at the program site from 28 June to 2 July.

This program has two related focus areas, each of which culminate in a 2-day conference.
*Turbulent boundary layers*, appearing on solid surfaces of bodies submerged in fluids and in channel and pipe flows, have been the focus of experimental and analytical investigations for almost a century. Still there are several unresolved issues even related to fairly basic mechanisms.

In *turbulent combustion* there are also many unresolved problems, such as how a turbulent premixed flame propagates. The importance of basic research in connection with energy production is evident. Simulations are important, because questions regarding the temperature distribution cannot easily be addressed experimentally.

*infinitely large or small extension* on all the systems that are considered. These theories fail, however, to address many important aspects, as *finiteness in extension* is apparent in most physical systems. The question is of highly generic nature and has significance within condensed matter physics, chemistry as well as biology.

This program will run in two installments: 15 February-1 March and 12-17 December 2010.

This four-week event joins a *school*, a *scientific program* and a *conference*, where teachers, students and scientists in computational science and engineering will be brought together to present, discuss and solve problems in areas of reserach involving multiple scales.

Understanding the origin of solar and stellar magnetic fields is one of the central problems of physics and astrophysics, and a key to understanding the cosmic magnetism, in general. The first two weeks of the programme are dedicated to stellar dynamo theory and observations, and the last two for solar magnetic activity, dynamos and data assimilation methods. The 5th-6th of October there is a special workshop in the honor of the 70th birthday of Professor Ilkka Tuominen.

Bringing together experts on neutron star dynamics, condensed matter and nuclear physics, surface layers and the magnetosphere, the key questions taht will be discussed are: What input from microphysics calculations do we need to build realistic theoretical models? What bounds can the dynamical models in conjunction with observations provide on the state of matter at extreme densities? How do we use observations to constrain these parameters? If a neutron star is oscillating, how does information of the oscillations propagate to the observers?

The aim of this workshop is to bring together a group of theorists with a broad and varied range of competences in numerical techniques, low energy effective theories, conformal field theory and lattice models, but with quantum Hall phenomena as a common interest.

The exciting prospect of exploring the Higgs sector of the Standard Model and its presumed extensions at the LHC has renewed interest in electroweak baryogenesis and the electroweak phase transition.

Relativistic jets are responsible for the huge luminosities seen in active galactic nuclei and gamma-ray bursts and are probably launched from the central black holes in these objects. The details of the jet launching mechanism, its acceleration, mechanisms of the energy dissipation, particle acceleration and the emission remain unknown.

The research topics to be covered at the program are: neutrino physics, dark matter, cosmology, supersymmetry, dark energy, inflation, extra dimensions, ultra-high-energy cosmic rays, supernovae, leptogenesis.

We intend to keep the program rather loose what concerns seminars, thus giving more time for actual research and discussing future research projects among the participants of the program.

The environmental and health effects of nanomaterials are of global concern, both in view of assessing the impact of nanomaterials discharged into nature and for a safe and transparent development of nanotechnology, especially in relation to novel applications in biomedicine.

The aim of this scientific program is to establish an international think-tank of researchers excelling in state-of-the-art computational and analytical theoretical methods to assess these and related issues.

Ever since the birth of superstring theory, interaction with geometry has been one of the primary driving forces that has led to progress. On one hand, string theory has generated many new geometrical concepts; and on the other hand new ideas from geometry have often found their first applications in string theory.

Within the program there will be the "Geometrical Aspects of String Theory" workshop and "The 22nd Nordic Network Meeting on Strings, Fields and Branes"

The Standard Model of Elementary Particle Physics suffers from a number of inconsistencies and requires extreme fine-tuning of parameters in some areas. This has led to the widespread belief that the Standard Model is the low-energy effective theory of some more fundamental theory in which all, or most, of the difficulties plaguing it are removed. The search for this more fundamental theory is one of the main enterprises of theoretical elementary particle physics.

Within the program there will be the "2nd Nordic Workshop on LHC and Beyond".

Statistical physics has recently applied been to understanding, analysis and design of large distributed information systems. These range from decoding algorithms (Belief Propagation) and phase transitions and typical-case hardness in combinatorial optimization problems to content distribution and dynamical phenomena on the Internet, to the modelling of distributed agent systems - Peer-to-Peer networks, auction mechanisms and more. The PhysDIS program aims to survey current trends in this exciting area, and foster new research into untapped directions.

The origin of astrophysical magnetic fields remains controversial. The intense progress in nonlinear and turbulent dynamo theory of the last ten years has prepared ground for imminent fundamental progress in this area. The programme will bring together experts in various relevant areas in order to (1) identify the critical problems to allow further rapid progress, (2) focus the effort on the most fruitful areas of research and (3) establish new collaborations, especially those between theoreticians and observers, that might ensure such a progress.

Homochirality is a unique property of living matter, and a property that gradually disappears after death. The origin of homochirality is therefore closely linked to the origin of life, which makes this topic a prominent research field in astrobiology.

Focus of the program: quantum fluids, Bose-Einstein condensates, supersolids, quantum hall systems, exotic states such as projected quantum fluid states of metallic hydrogen, topological defects and vortex matter in quantum fluids.

Phone: +46 8 5537 8473, Fax: +46 8 5537 8404, E-mail: info@nordita.org

*nw-4.10 (1079)25 Jan 2023*

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