Tuesday, 4 February, 2020
Tobias Diez, Tudor S. Ratiu

The space of smooth sections of a symplectic fiber bundle carries a natural symplectic structure. We provide a general framework to determine the momentum map for the action of the group of...

Friday, 31 January, 2020
Jürg Fröhlich, Antti Knowles, Benjamin Schlein, Vedran Sohinger

We review some recent results on interacting Bose gases in thermal equilibrium. In particular, we study the convergence of the grand-canonical equilibrium states of such gases to their mean-...

Wednesday, 29 January, 2020
Giovanni Canepa, Alberto S. Cattaneo, Michele Schiavina

An explicit, geometric description of the first-class constraints and their Poisson brackets for gravity in the Palatini-Cartan formalism (in space-time dimension greater than three) is given....

Wednesday, 29 January, 2020
Oksana Berezniuk, Alessio Figalli, Raffaele Ghigliazza, Kharen Musaelian

We introduce a notion of "effective dimension" of a statistical model based on the number of cubes of size 1/\sqrt{n} needed to cover the model space when endowed with the Fisher Information...

Tuesday, 21 January, 2020
Enis Belgacem, Yves Dirian, Andreas Finke, Stefano Foffa, Michele Maggiore

We provide a systematic and updated discussion of a research line carried out by our group over the last few years, in which gravity is modified at cosmological distances by the introduction of...

Monday, 20 January, 2020
Andrea Cavaglia, David Grabner, Nikolay Gromov, Amit Sever

We introduce a new class of operators in any theory with a 't Hooft large-N limit that we call colour-twist operators. They are defined by twisting the colour-trace with a global symmetry...

Sunday, 19 January, 2020
Ilia Itenberg, Grigory Mikhalkin

For a real K3-surface X, one can introduce areas of connected components of the real point set RX of X using a holomorphic symplectic form of X. These areas are defined up to simultaneous...

Tuesday, 14 January, 2020
Dmitry Ioffe, Sébastien Ott, Yvan Velenik, Vitali Wachtel

We consider nearest-neighbor two-dimensional Potts models, with boundary conditions leading to the presence of an interface along the bottom wall of the box. We show that, after a suitable...

Monday, 6 January, 2020
Jürg Fröhlich, Antti Knowles, Benjamin Schlein, Vedran Sohinger

We prove that the grand canonical Gibbs state of an interacting quantum Bose gas converges to the Gibbs measure of a nonlinear Schrödinger equation in the mean-field limit, where the density of...

Monday, 6 January, 2020
Nicolas Gisin

Physics is formulated in terms of timeless, axiomatic mathematics. A formulation on the basis of intuitionist mathematics, built on time-evolving processes, would offer a perspective that is...

Nat. Phys. (2020)
Thursday, 2 January, 2020
Adam Kanigowski, Mariusz Lemańczyk, Corinna Ulcigrai

The Ratner property, a quantitative form of divergence of nearby trajectories, is a central feature in the study of parabolic homogeneous flows. Discovered by Marina Ratner and used in her...

Invent. math. (2020)
Thursday, 2 January, 2020
Gian Michele Graf, Hansueli Jud, Clément Tauber

We study the two-dimensional rotating shallow-water model describing Earth's oceanic layers. It is formally analogue to a Schrödinger equation where the tools from topological insulators are...