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Related papers: On accumulated spectrograms for Gabor frames

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This work establishes novel optimum mixing bounds for the Glauber dynamics on the Hard-core and Ising models. These bounds are expressed in terms of the local connective constant of the underlying graph $G$. This is a notion of effective…

Discrete Mathematics · Computer Science 2025-04-29 Charilaos Efthymiou

In this work we show that if the frame property of a Gabor frame with window in Feichtinger's algebra and a fixed lattice only depends on the parity of the window, then the lattice can be replaced by any other lattice of the same density…

Functional Analysis · Mathematics 2019-12-06 Markus Faulhuber

We study the construction of Gabor frames and wavelet frames for Weyl-Heisenberg group and extended affine group by using contraction between the affine group and the Weyl-Heisenberg group due to Subag, Baruch, Birman and Mann. Firstly, we…

Functional Analysis · Mathematics 2022-08-02 Divya Jindal , Lalit Kumar Vashisht

In this work we derive a simple argument which shows that Gabor systems consisting of odd functions of $d$ variables and symplectic lattices of density $2^d$ cannot constitute a Gabor frame. In the 1--dimensional, separable case, this is a…

Functional Analysis · Mathematics 2018-12-07 Markus Faulhuber

Let G be a real Lie group and H a lattice or, more generally, a closed subgroup of finite covolume in G. We show that the unitary representation lambda_{G/H} of G on L^2(G/H) has a spectral gap, that is, the restriction of lambda_{G/H} to…

Group Theory · Mathematics 2010-08-04 Bachir Bekka , Yves Cornulier

We build on our recent results on the Lipschitz dependence of the extreme spectral values of one-parameter families of pseudodifferential operators with symbols in a weighted Sj\"ostrand class. We prove that larger symbol classes lead to…

Functional Analysis · Mathematics 2024-07-26 Karlheinz Gröchenig , José Luis Romero , Michael Speckbacher

We investigate the relation between two different mathematical problems: the construction of bounds on sphere packing density using Cohn-Elkies functions and the construction of Gabor frames for signal analysis. In particular, we present a…

Functional Analysis · Mathematics 2022-12-14 Yuri Manin , Matilde Marcolli

We prove bounds for a class of unital homomorphisms arising in the study of spectral sets, by involving extremal functions and vectors. These are used to recover three celebrated results on spectral constants by Crouzeix--Palencia,…

Functional Analysis · Mathematics 2023-02-13 Felix L. Schwenninger , Jens de Vries

Let G be a second countable, locally compact group and let f be a continuous Herz-Schur multiplier on G. Our main result gives the existence of a (not necessarily uniformly bounded) strongly continuous representation on a Hilbert space,…

Representation Theory · Mathematics 2010-01-05 Troels Steenstrup

In recent work on equiangular lines, Jiang, Tidor, Yuan, Zhang, and Zhao showed that a connected bounded degree graph has sublinear second eigenvalue multiplicity. More generally they show that there cannot be too many eigenvalues near the…

Probability · Mathematics 2024-01-17 Mikolaj Fraczyk , Ben Hayes , Madhu Sudan , Yufei Zhao

The Lagrange and Markov spectra have been studied since late 19th century, concerning badly approximable real numbers. The Mordell-Gruber spectrum has been studied since 1936, concerning the supremum of the area of a rectangle centered at…

Dynamical Systems · Mathematics 2024-07-15 Ruichong Zhang

Investigating the performance of different methods is a fundamental problem in graph partitioning. In this paper, we estimate the so-called detectability threshold for the spectral method with both unnormalized and normalized Laplacians in…

Social and Information Networks · Computer Science 2015-06-10 Tatsuro Kawamoto , Yoshiyuki Kabashima

We study the spectral bounds of self-adjoint operators on the Hilbert space of square-integrable functions, arising from the representation theory of the Heisenberg group. Interestingly, starting either with the von Neumann lattice or the…

Classical Analysis and ODEs · Mathematics 2025-04-28 Markus Faulhuber , Anupam Gumber , Irina Shafkulovska

It is well known that the Gabor expansions converge to identity operator in weak* sense on the Wiener amalgam spaces as sampling density tends to infinity. In this paper we prove the convergence of Gabor expansions to identity operator in…

Functional Analysis · Mathematics 2016-07-22 Anirudha Poria

We study the spectral properties of a system of electrons interacting through long-range Coulomb potential on a one-dimensional chain. When the interactions dominate over the electronic bandwidth, the charges arrange in an ordered…

Strongly Correlated Electrons · Physics 2009-11-13 S. Fratini , G. Rastelli

Let $f: \CN \rightarrow \C $ be a reduced polynomial map, with $D=f^{-1}(0)$, $\U=\CN \setminus D$ and boundary manifold $M=\partial \U$. Assume that $f$ is transversal at infinity and $D$ has only isolated singularities. Then the only…

Algebraic Topology · Mathematics 2016-07-20 Yongqiang Liu , Laurentiu Maxim

We study the eigenvalue profile of concentration operators (multiplication by an indicator function followed by projection) acting on reproducing kernel Hilbert spaces. The spectral profile of such operators provides a useful notion of…

Spectral Theory · Mathematics 2026-04-09 Felipe Marceca , José Luis Romero , Michael Speckbacher , Lisa Valentini

We show that the possibility to address and image single sites of an optical lattice, now an experimental reality, allows to measure the frequency-resolved local particle and hole spectra of a wide variety of one- and two-dimensional…

Quantum Gases · Physics 2015-10-21 Adrian Kantian , Ulrich Schollwöck , Thierry Giamarchi

We prove a generalization of the Expander Mixing Lemma for arbitrary (finite) simplicial complexes. The original lemma states that concentration of the Laplace spectrum of a graph implies combinatorial expansion (which is also referred to…

Combinatorics · Mathematics 2018-04-11 Ori Parzanchevski

In a recent paper in Appl. Comput. Harmon. Anal. 38(2), 196--221 (2014) we have introduced and studied the notion of weak Hamiltonian deformation of a Gabor (=Weyl-Heisenberg) frame. In this Note we use these results to prove that one can…

Functional Analysis · Mathematics 2015-12-15 Maurice A. de Gosson