Nordita welcomes Professor John S. Wettlaufer, who is spending his second sabbatical with us after a successful stay back in 2008; see the Nordita Newsletter 2008, Issue 3. John is the A.M. Bateman Professor of Geophysics, Physics and Applied Mathematics at Yale University. His training is in the statistical physics of phase transitions but over the years it has branched out substantially across many disciplines in soft condensed matter physics and applied mathematics with impinging upon biophysics, geophysics and most recently, due to his time here previously, astrophysics.

His stay at Nordita is supported by the Wenner-Gren Foundation. He will
be working on the stochastic dynamics generally with applications to
abrupt changes in Arctic climate and in fluid dynamics generally. In the
former case, the basic problem is one of predicting the future using
imperfect and highly variable global climate computer models versus
the questionable activity of extrapolating to the future using a 31
year time series of high resolution satellite data. This leaves a spate
of possibilities for "simple" mathematical models, rigorous studies of
the origin and nature of variability and periodicity, and a focus on the
multiplicity of time scales embedded in the data, examined in the context
of the singularity spectrum of multifractals. These approaches have an
origin in the statistical mechanics of fluctuating systems with major
insights originating in stochastic and numerical models of turbulence,
dynamos and a wide variety of other systems. He hopes also to begin
the process of incorporating the microphysical conditions for planetary
accretion studied during his previous visit into the pencil code.
He also looks forward to enjoying the wide range of intellectual pleasures
offered by the Nordita community and its programs as well as the plentiful
offerings of the city of Stockholm.

Nordita welcomes **Marianne Persson Söderlind** who arrived as Chief Administrator in August. Marianne has been working within university administration during her whole professional career, with questions related to personnel, budget, and education. For the past 20 years she has primarily been concerned with international issues, first at Umeå university and Mid Sweden university and later at KTH. She was responsible for the International Office at KTH for ten years, until it was merged into the office of Corporate Communications and International Relations. Her latest project was supporting the master school within the EIT ICT Labs project (EIT = European Institute for Innovation and Technology, ICT = Information and Communications Technology) during its start-up phase at KTH.

**Oksana Manyuhina** received her PhD from Radboud University of Nijmegen in 2009 and was a postdoctoral fellow at the Ecole Normale Supérieure in Paris before coming to Nordita. Her research is in the area of soft condensed matter, in particular, she is interested in shape transformations of self-assembled structures, instability patterns in thin liquid crystal films and in the motility of cells.

**Juha Suorsa** received his PhD in 2011 from the University of Oslo. His research is in theoretical condensed matter physics with focus on topological and strongly correlated phases of matter. He is also interested in gauge/gravity duality and its applications to condensed matter.

**Daniela Fitger** left her post as Chief Administrator of Nordita in June to take up a position with Kooperation Utan Gränser. We thank Daniela for her time and services at Nordita and wish her good luck in her new job.

On July 18th (with an addendum on July 22nd) astrophysicists **Niccolo Bucciantini**, **Piyali Chatterjee**, **Gustavo Guerrero**, and **Matthias Rheinhardt** organized an emergency brain-storming evening session after the discovery that their scientific lifetime at Nordita is not unlimited (AKA goodbye party).

During the summer, Nordita Fellow **Annica Black-Schaffer** moved to the Materials Theory group at Uppsala University to take up a forskarassistenttjänst (assistant professor) position funded by a grant from Vetenskapsrådet.

We wish all of them good fortune and success in their future careers.

Nordita PhD students **Jörn Warnecke** and **Koen Kemel** have successfully defended their licentiate theses, "Flux emergence, flares and coronal mass ejections driven by dynamo action underneath the solar surface" (6 May) and
"Mean-field theory in magneto-hydrodynamics and the generation of magnetic flux concentrations" (16 August). Both students are supported by the ERC Astrophysical Dynamos project.
For pictures of both events, click here.

Applications for Nordita Fellowships will open in September with a **November 15** deadline. An announcement will be posted on the Nordita home page and applications are to be submitted via the Nordita on-line application system. Appointments are for two years starting September 1, 2012 or some other date to be agreed upon. The fellowships are intended for scientists who have a recent PhD, completed less than 5 years before the starting date of the fellowship, and wish to carry out research in fields represented at Nordita. Candidates working in other areas will be considered when it is scientifically justified.

The **Nordita School in Theoretical Particle Physics** will take place at Nordita in the period **January 9-20, 2012** and is organized by **Paolo Di Vecchia**, **Troels Harmark**, **Lárus Thorlacius**, and **Konstantin Zarembo**. It is the third annual winter school organized at Nordita in Stockholm.

The school is mainly intended for PhD students and young postdocs from the Nordic countries. The topics at the school include lectures on the *standard model of particle physics, beyond the standard model physics, non-perturbative aspects of quantum field theory, cosmology, black holes, string theory, holography and AdS/CFT, applications of AdS/CFT, and the experimental search for quantum gravity*.

Lecturers will include P. Di Vecchia (Nordita), G. Ferretti (Chalmers, Göteborg), S. Hannestad (University of Aarhus), T. Harmark (Nordita), S. Hossenfelder (Nordita), N. A. Obers (Niels Bohr Institute), A. Raklev (Oslo), F. Sannino (SDU, Odense), L. Thorlacius (Nordita) and K. Zarembo (Nordita)

The 2012 Nordita School in Theoretical Particle Physics is supported by NordForsk through a grant of 400,000 NOK awarded to Troels Harmark, chairman of the organizing committee.

**Axel Brandenburg**
received a grant of 100,000 SEK from VR to support a workshop dedicated to the discussion of the connection between several approaches to the dynamo problem, including mathematics, turbulent magnetohydrodynamics, numerical simulations, interpretation of experimental and observational data. The meeting was part of the Nordita program Dynamo, Dynamical Systems and Topology, which was motivated by the fact that the turbulent dynamo is a long-standing fundamental problem of physics and astrophysics. While substantial progress has been recently achieved in numerical simulations, theory and observations, the underlying principles of dynamo mechanisms under various conditions are not fully understood.

**Ralf Eichhorn** received a grant of 10,000 ? under the European Science Foundation (ESF) activity 'Exploring the Physics of Small Devices (EPSD)' to support the Nordita Scientific Program Foundations and Applications of Non-Equilibrium Statistical Mechanics to be held between September 19 and October 14, 2011.

**Troels Harmark** received a grant of 5000 ? from the Holograv Network (Holographic methods for strongly coupled systems) sponsored by the European Science Foundation to organize an intensive one-week workshop as part of the Nordita Program 'The Holographic way: String theory, Gauge theory and Black holes', organized by Troels Harmark, Niels A Obers (Niels Bohr Institute) and Marta Orselli (Niels Bohr Institute) in October 2012.

**Sabine Hossenfelder**, jointly with Fotini Markopoulou of the Perimeter Institute, has been awarded a $10,000 grant from FQXi (Foundational Questions Institute) to support a workshop on 'Non-locality: Aspects and Consequences', focussing on non-locality in quantum foundations, quantum information, and
quantum gravity (including string theory and emergent gravity). The aim of the workshop is to bring together researchers working on various aspects of nonlocality, first to clarify the notion, and then to find commonalities as well as differences and discuss the relevance for making headway on quantum gravity and understanding the foundations of quantum mechanics. The workshop is to be held at Nordita in Stockholm and is tentatively scheduled for May 23 - 25, 2012.

**Dhrubaditya Mitra**
received a grant of 100,000 SEK from VR and 3000 ? from CNRS to support a Nordita conference with the title The solar course, the chemic force, and the speeding change of water, which is a multidisciplinary meeting to celebrate the 70th birthday of Professor Uriel Frisch. The principal scientific topics include
fluid turbulence, MHD turbulence and turbulent dynamo, optimal transport and its applications in astrophysics, cosmology, biophysics, geophysical, and nonequilibrium statistical physics.
Nonlinearity and a wide range of relevant length and time scales are common threads running through all these subjects. It is hence important to notice the underlying unity which can give rise to cross-fertilization of ideas.

- from August 22 to September 16 2011

- The aim of the program 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.

- from September 19 to October 14 2011

- 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).

- from November 1 to November 30 2011

- 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 (including 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, and topological field theories.

- 17?21 October 2011

- A multidisciplinary program to celebrate the 70th birthday of Uriel Frisch. The principal scientific topics are going to be turbulence, nonlinear dynamics, statistical mechanics, atmospheric and biological applications of nonlinear physics. A tentative list of themes includes Fluid turbulence, Turbulent dynamo, Lattice-gas, Lattice-Boltzmann, Optimal transport and applications, Biologically inspired problems, Weather and Climate physics.

- Coordinator: Dhrubaditya Mitra

**Eddy Ardonne** will give a PhD course at Stockholm University on **Conformal Field Theory** (http://www.nordita.org/~ardonne/cft-course.html), starting September 2.

**Konstantin Zarembo** will give a course in **Quantum Field Theory** at the Perimeter Institute, Waterloo, Canada (http://www.perimeterscholars.org/course-curriculum.html) in October.

The next meeting of the Nordita Board will take place in Stockholm on **September 23, 2011**.

→ Link to electronic preprints: **www.nordita.org/preprints**

The following preprints have been posted to the Nordita on-line archive since the last newsletter issue:

- 2011-034
*Random trees with superexponential branching weights*- Svante Janson, Thordur Jonsson and Sigurdur Örn Stefánsson

- 2011-035
- "Charge Fractionalization on Quantum Hall Edges"
- Mats Horsdal, Marianne Rypestøl, Hans Hansson, Jon Magne Leinaas

- 2011-036
- "Negative effect of turbulent convection on mean magnetic pressure"
- P. J. Käpylä, A. Brandenburg, N. Kleeorin, M.J. Mantere, I. Rogachevskii
- MNRAS (submitted)

- 2011-037
- "Loading of p-band bosons in optical lattices"
- Jonas Larson and Jani-Petri Martikainen

- 2011-038
- "Multiplication law and S transform for non-hermitian random matrices"
- Z.Burda, R.A.Janik, M.A.Nowak

- 2011-039
- "Dynamic Multiscaling in Two-dimensional Fluid Turbulence"
- S.S. Ray, D. Mitra, P. Perlekar, and R. Pandit
- Phys. Rev. Lett. (submitted)

- 2011-040
- "Pumping velocity in homogeneous helical turbulence with shear"
- I. Rogachevskii, N. Kleeorin, P. J. Käpylä, A. Brandenburg
- Phys. Rev. E (submitted)

- 2011-041
- "Flow-turbulence interaction in magnetic reconnection"
- Nobumitsu Yokoi, Masahiro Hoshino

- 2011-042
- "Effect of coupling asymmetry on mean-field solutions of direct and inverse Sherrington-Kirkpatrick model"
- Jason Sakellariou, Yasser Roudi, Marc Mezard, John Hertz

- 2011-043
- "Testing super-deterministic hidden variables theories"
- Sabine Hossenfelder

- 2011-044
- "The dual string ?-model of the SU_q(3) sector"
- V. Giangreco M. Puletti and T. Månsson

- 2011-045
- "A model of driven and decaying magnetic turbulence in a cylinder"
- Koen Kemel, Axel Brandenburg and Hantao Ji
- submitted to Phys Rev E

- 2011-046
- "Bosonic and fermionic dipoles on a ring"
- S. Zoellner, G. M. Bruun, C. J. Pethick, and S. M. Reimann
- Phys. Rev. Lett. 107, 035301 (2011)

- 2011-047
- "Majorana fermions in spin-orbit coupled ferromagnetic Josephson junctions"
- Annica M. Black-Schaffer and Jacob Linder

- 2011-048
- "Wilson Loops in N=2 Super-Yang-Mills from Matrix Model"
- F. Passerini and K. Zarembo

- 2011-049
- "Blackfolds in Supergravity and String Theory"
- R. Emparan, T. Harmark, V. Niarchos and N. A. Obers

- 2011-050
- "Toroidal $p$-brane vortices, anharmonic oscillators and (hyper)elliptic solutions"
- A.A. Zheltukhin

- 2011-051
- "Short GRBs with Extended Emission from Magnetar Birth: Jet Formation and Collimation"
- Bucciantini, N., Metzger, B.D., Thompson, T.A., Quataert, E.
- Monthly Notices Roy. Astron. Soc., submittted (2011)

- 2011-052
- "Subcritical small-scale dynamos at low magnetic Prandtl numbers"
- Axel Brandenburg
- Astrophys. J. (submitted)

- 2011-053
- "Starspots due to large-scale vortices in rotating turbulent convection"
- Käpylä, P. J., Mantere, M. J. & Hackman, T.
- Astrophys. J. (submitted)

- 2011-054
- "Catastrophic quenching in alpha-Omega dynamos revisited"
- A. Hubbard, A. Brandenburg
- Astrophys. J. (submitted)

- 2011-055
- "The structure of spinful quantum Hall states: a squeezing perspective"
- Eddy Ardonne, Nicolas Regnault

- 2011-056
- "Tidal deformations of neutron stars: The role of stratification and elasticity"
- A.J. Penner, N. Andersson, L. Samuelsson, I. Hawke, D.I. Jones

- 2011-057
- "Ising Models for Inferring Network Structure From Spike Data"
- John Hertz, Yasser Roudi, Joanna Tyrcha
- To appear in "Principles of Neural Coding", edited by Stefano Panzeri and Rodrigo Quian Quiroga

- 2011-058
- "Properties of the negative effective magnetic pressure instability"
- Koen Kemel, Axel Brandenburg, Nathan Kleeorin and Igor Rogachevskii
- Astron. Nachr. (submitted)

- 2011-059
- "Scaling and intermittency in incoherent ?-shear dynamo"
- Dhrubaditya Mitra, Axel Brandenburg
- MNRAS (submitted)

- 2011-060
- "Turbulent transport in stratified and/or rotating turbulence"
- A. Brandenburg, K.-H. Radler, K. Kemel
- Astron. Astrophys. (submitted)

- 2011-061
- "Plasma flow vs. magnetic feature-tracking speeds in the Sun"
- G. Guerrero, M. Rheinhardt, A. Brandenburg, M. Dikpati
- Monthly Notices Roy. Astron. Soc., submittted (2011)

- 2011-062
- "Quantum entanglement of bound particles under free center of mass dispersion"
- Fernanda Pinheiro, A. F. R. de Toledo Piza

- 2011-063
- "Cross-helicity effects and turbulent transport in magnetohydrodynamic flow"
- N. Yokoi, G. Balarac
- Journal of Physics Conference Series: 13th European Turbulence Conference (ETC13)

- 2011-064
- "The NHXM observatory"
- Tagliaferri G. et al. (Bucciantini N. as member of the Science Team)
- Experimental Astronomy

- 2011-065
- "Lagrangian perturbation theory for a superfluid immersed in an elastic neutron star crust"
- N. Andersson, B. Haskell, L. Samuelsson
- Monthly Notices Roy. Astron. Soc. (in press)

- 2011-067
- "Tomographic-PIV measurement of the flow around a zigzag boundary layer trip"
- G. E. Elsinga, J. Westerweel
- Exp Fluids, DOI: 10.1007/s00348-011-1153-8

- 2011-069
- "Thermodynamics of Dyonic Lifshitz Black Holes"
- T. Zingg

If you have information about meetings or other items that would be useful to include in Nordita News, please send it to Anne Jifält, Nordita, email: anne@kth.se.

For back issues of the Nordita newsletter, see http://www.nordita.org/news/about/archive/issues/index.php