English
Related papers

Related papers: Phase retrieval for nilpotent groups

200 papers

Suppose that $G$ is a finite group and $H$ is a nilpotent subgroup of $G$. If a character of $H$ induces an irreducible character of $G$, then the generalized Fitting subgroup of $G$ is nilpotent.

Representation Theory · Mathematics 2019-02-27 Zoltan Halasi , Attila Maroti , Gabriel Navarro , Pham Huu Tiep

The classical phase retrieval problem involves estimating a signal from its Fourier magnitudes (power spectrum) by leveraging prior information about the desired signal. This paper extends the problem to compact groups, addressing the…

Signal Processing · Electrical Eng. & Systems 2025-01-08 Tamir Bendory , Dan Edidin

We continue the study of glider representations of finite groups $G$ with given structure chain of subgroups $e \subset G_1 \subset \ldots \subset G_d = G$. We give a characterization of irreducible gliders of essential length $e \leq d$…

Representation Theory · Mathematics 2019-10-15 Frederik Caenepeel , Fred Van Oystaeyen

The main result of this paper states that phase retrieval in infinite-dimensional Hilbert spaces is never uniformly stable, in sharp contrast to the finite dimensional setting in which phase retrieval is always stable. This leads us to…

Functional Analysis · Mathematics 2016-06-28 Jameson Cahill , Peter G. Casazza , Ingrid Daubechies

We give an algorithm for computing the irreducible admissible representations of a real reductive group with regular integral infinitesimal character. This algorithm has been implemented on a computer, as part of the Atlas of Lie Groups and…

Representation Theory · Mathematics 2008-07-22 Jeffrey Adams , Fokko du Cloux

We give parameterizations of the irreducible representations of finite groups of Lie type in their defining characteristic.

Representation Theory · Mathematics 2016-09-12 Olivier Brunat , Frank Lübeck

Answering a question of I. M. Isaacs, we show that the largest degree of irreducible complex representations of any finite non-abelian simple group can be bounded in terms of the smaller degrees. We also study the asymptotic behavior of…

Representation Theory · Mathematics 2014-02-26 Michael Larsen , Gunter Malle , Pham Huu Tiep

In this article, we determine all inequivalent irreducible rational matrix representations of groups of order $p^5$, where $p$ is an odd prime. We also derive combinatorial formulations for the Wedderburn decomposition of rational group…

Representation Theory · Mathematics 2025-04-02 Ram Karan Choudhary , Sunil Kumar Prajapati

In this paper we prove two results regarding reconstruction from magnitudes of frame coefficients (the so called "phase retrieval problem"). First we show that phase retrievability as an algebraic property implies that nonlinear maps are…

Functional Analysis · Mathematics 2015-06-09 Radu Balan , Dongmian Zou

This paper discusses the connection between the phase retrieval problem and permutation invariant embeddings. We show that the real phase retrieval problem for $\mathbb{R}^d/O(1)$ is equivalent to Euclidean embeddings of the quotient space…

Functional Analysis · Mathematics 2023-10-31 Radu Balan , Efstratios Tsoukanis

In this note we prove that reconstruction from magnitudes of frame coefficients (the so called "phase retrieval problem") can be performed using Lipschitz continuous maps. Specifically we show that when the nonlinear analysis map…

Functional Analysis · Mathematics 2014-03-11 Radu Balan , Dongmian Zou

The main result of this article is an application of the theory of invariant convex cones of Lie algebras to the study of unitary representations of Lie supergroups. It also includes an exposition of recent results of the second author on…

Representation Theory · Mathematics 2010-12-14 Karl-Hermann Neeb , Hadi Salmasian

The description of irreducible finite dimensional representations of finite dimensional solvable Lie superalgebras over complex numbers given by V.~Kac is refined. In reality these representations are not just induced from a polarization…

Representation Theory · Mathematics 2007-05-23 Alexander Sergeev

The orbital varieties are the irreducible components of the intersection between a nilpotent orbit and a Borel subalgebra of the Lie algebra of a reductive group. There is a geometric correspondence between orbital varieties and irreducible…

Representation Theory · Mathematics 2018-10-31 Lucas Fresse , Anna Melnikov

We define basic notions in the category of conic representations of a topological group and prove elementary facts about them. We show that a conic representation determines an ordinary dynamical system of the group together with a…

Dynamical Systems · Mathematics 2019-03-25 Matan Tal

If chi is an irreducible character of a finite group G then the support of chi is the subset of G on which chi does not vanish. In this note, we study the supports of characters of certain classes of p-groups (a p-group is a finite group of…

Representation Theory · Mathematics 2013-07-23 Tom Wilde

Let G be a Lie group, $g = Lie(G)$ - its Lie algebra, $g*$ - the dual vector space and $\widehat G$ - the set of equivalence classes of unitary irreducible representations of $G$. The orbit method [1] establishes a correspondence between…

Representation Theory · Mathematics 2025-07-08 Dmitry Fuchs , Alexandre Kirillov

We prove that the extended Poincare group in (1+1) dimensions is non-nilpotent solvable exponential, and therefore that it belongs to type I. We determine its first and second cohomology groups in order to work out a classification of the…

Mathematical Physics · Physics 2009-11-07 R. O. de Mello , V. O. Rivelles

We answer a number of open problems concerning phase retrieval and phase retrieval by projections. In particular, one main theorem classifies phase retrieval by projections via collections of sequences of vectors allowing norm retrieval.…

Functional Analysis · Mathematics 2016-01-20 Jameson Cahill , Peter G. Casazza , John Jasper , Lindsey M. Woodland

The generalized phase retrieval problem over compact groups aims to recover a set of matrices -- representing an unknown signal -- from their associated Gram matrices. This framework generalizes the classical phase retrieval problem, which…

Signal Processing · Electrical Eng. & Systems 2025-11-20 Tal Amir , Tamir Bendory , Nadav Dym , Dan Edidin