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Local existence and well posedness for a class of solutions for the Euler Poisson system is shown. These solutions have a density $\rho$ which either falls off at infinity or has compact support. The solutions have finite mass, finite…

Analysis of PDEs · Mathematics 2017-09-26 Uwe Brauer , Lavi Karp

We investigate the phase diagram of dipolar fermions with aligned dipole moments in a two-dimensional (2D) bilayer. Using a version of the Singwi-Tosi-Land-Sjolander scheme recently adapted to dipolar fermions in a single layer [M. M.…

Quantum Gases · Physics 2013-04-30 F. M. Marchetti , M. M. Parish

We establish effective versions of Oppenheim's conjecture for generic inhomogeneous quadratic forms. We prove such results for fixed shift vectors and generic quadratic forms. When the shift is rational we prove a counting result which…

Number Theory · Mathematics 2020-08-18 Anish Ghosh , Dubi Kelmer , Shucheng Yu

The derivation of the state of the art tensorial versions of Fundamental Measure Theory (a form of classical Density Functional Theory for hard spheres) are re-examined in the light of the recently introduced concept of global stability of…

Statistical Mechanics · Physics 2021-01-04 James F. Lutsko

In this paper we suggest new effective criteria for the density property. This enables us to give a trivial proof of the original Anders\'en-Lempert result and to establish (almost free of charge) the algebraic density property for all…

Complex Variables · Mathematics 2009-11-13 Shulim Kaliman , Frank Kutzschebauch

In this paper we propose a method for automatic local time adap- tation of the spectrogram of an audio signal, based on its decomposition within a Gabor multi-frame. The sparsity of the analyses within each individual frame is evaluated…

Sound · Computer Science 2011-09-29 M. Liuni , A. Röbel , M. Romito , X. Rodet

A density-functional theory is established for inhomogeneous superfluids at finite temperature, subject to time-dependent external fields in isothermal conditions. After outlining parallelisms between a neutral superfluid and a charged…

Statistical Mechanics · Physics 2009-10-31 M. L. Chiofalo , M. P. Tosi

A new method, dual-space cluster expansion, is proposed to study classical phases transitions in the continuum. It relies on replacing the particle positions as integration variables by the momenta of the relative displacements of particle…

Mathematical Physics · Physics 2025-11-18 Andras Suto

This note provides elementary proofs for necessary density conditions for frames and Riesz sequences in the lattice orbit of a discrete series representation that involve the projective stabiliser of the vector. The presented approach…

Functional Analysis · Mathematics 2025-08-21 Jordy Timo van Velthoven

We investigate the structural properties of dual systems for nonstationary Gabor frames. In particular, we prove that some inverse nonstationary Gabor frame operators admit a Walnut-like representation, i.e. the operator acting on a…

Functional Analysis · Mathematics 2017-08-01 Nicki Holighaus

In this paper, we introduce Gabor shearlets, a variant of shearlet systems, which are based on a different group representation than previous shearlet constructions: they combine elements from Gabor and wavelet frames in their construction.…

Functional Analysis · Mathematics 2013-03-27 Bernhard G. Bodmann , Gitta Kutyniok , Xiaosheng Zhuang

Let $G$ be a second-countable amenable group with a uniform $k$-approximate lattice $\Lambda$. For a projective discrete series representation $(\pi, \mathcal{H}_{\pi})$ of $G$ of formal degree $d_{\pi} > 0$, we show that $D^-(\Lambda) \geq…

Functional Analysis · Mathematics 2023-10-05 Ulrik Enstad , Jordy Timo van Velthoven

We investigate the completeness of Gabor systems with respect to several classes of window functions on rational lattices. Our main results show that the time-frequency shifts of every finite linear combination of Hermite functions with…

Mathematical Physics · Physics 2016-11-29 Karlheinz Gröchenig , Antti Haimi , José Luis Romero

This paper presents a set of new conditions on the augmented density of a spherical anisotropic system that is necessary for the underlying two-integral phase-space distribution function to be non-negative. In particular, it is shown that…

Mathematical Physics · Physics 2011-06-07 J. An

The equilibrium properties of classical self-gravitating systems in the grand canonical ensemble are studied by using the correspondence with an euclidean field theory with infrared and ultraviolet cutoffs. It is shown that the system…

Astrophysics · Physics 2007-05-23 Victor Laliena

Starting with an integrable unitary representation of a locally compact group and its associated voice transform, coorbit theory describes the construction and investigation of the so-called coorbit spaces. A coorbit space consists of…

Functional Analysis · Mathematics 2024-01-24 Jan Zimmermann

Inspired by the concept of coherent frozen waves, this paper introduces one possible theoretical framework of its partially coherent version, a frozen spatial coherence, in which a desired two-point correlation structure of an optical field…

Optics · Physics 2022-06-22 M. A. Pinto , P. A. Brandão

We consider the Fock space weighted by $e^{-\alpha |z|^{2}}$, of entire and quasi-periodic (modulo a weight dependent on $\nu $) functions on ${C}$. The quotient space $\mathbb{C}/\mathbb{Z}$, called `The flat cylinder', is represented by…

Functional Analysis · Mathematics 2025-08-14 Luis Daniel Abreu , Franz Luef , Mohammed Ziyat

We investigate properties of two-dimensional bilayered dipolar Bose condensed gases in a weak random potential with Gaussian correlation at zero temperature. Here the dipoles are oriented perpendicularly to the layers and in…

Disordered Systems and Neural Networks · Physics 2020-09-01 Abdelaali Boudjemaa , Redaouia Keltoum

The theory of Gabor frames of functions defined on finite abelian groups was initially developed in order to better understand the properties of Gabor frames of functions defined over the reals. However, during the last twenty years the…

Rings and Algebras · Mathematics 2020-05-04 Romanos-Diogenes Malikiosis