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Concept

Treillis des sous-groupes

Publications associées (27)

Toroidal families and averages of L-functions, I

Philippe Michel

We initiate the study of certain families of L-functions attached to characters of subgroups of higher-rank tori, and of their average at the central point. In particular, we evaluate the average of the values L( 2 1 , chi a )L( 21 , chi b ) for arbitrary ...

Polish Acad Sciences Inst Mathematics-Impan2024

Dense Packings via Lifts of Codes to Division Rings

Vlad Serban, Nihar Prakash Gargava

obtain algorithmically effective versions of the dense lattice sphere packings constructed from orders in Q-division rings by the first author. The lattices in question are lifts of suitable codes from prime characteristic to orders O in Q-division rings a ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

Subgroups of elliptic elements of the Cremona group

Christian Lucius Urech

The Cremona group is the group of birational transformations of the complex projective plane. In this paper we classify its subgroups that consist only of elliptic elements using elementary model theory. This yields in particular a description of the struc ...

2021

On Herz'S Extension Theorem

Antoine Derighetti

We present a self-contained proof of the following famous extension theorem due to Carl Herz. A closed subgroup H of a locally compact group G is a set of p-synthesis in G if and only if, for every u is an element of A(p)(H) boolean AND C-00(H) and for eve ...

TUSI MATHEMATICAL RESEARCH GROUP2019

Structural Properties Of Dendrite Groups

Nicolas Monod

Let G be the homeomorphism group of a dendrite. We study the normal subgroups of G. For instance, there are uncountably many nonisomorphic such groups G that are simple groups. Moreover, these groups can be chosen so that any isometric G-action on any metr ...

AMER MATHEMATICAL SOC2019

Hyperbolicity as an obstruction to smoothability for one-dimensional actions

Yash Lodha

Ghys and Sergiescu proved in the 1980s that Thompson's group T, and hence F, admits actions by C-infinity diffeomorphisms of the circle. They proved that the standard actions of these groups are topologically conjugate to a group of C-infinity diffeomorphi ...

GEOMETRY & TOPOLOGY PUBLICATIONS2019

Extensive amenability and an application to interval exchanges

Nicolas Monod, Nicolas Matte Bon

Extensive amenability is a property of group actions which has recently been used as a tool to prove amenability of groups. We study this property and prove that it is preserved under a very general construction of semidirect products. As an application, w ...

2018

Elliptic curves over a finite field and the trace formula

Ian Nicholas Petrow

We prove formulas for power moments for point counts of elliptic curves over a finite field k such that the groups of k-points of the curves contain a chosen subgroup. These formulas express the moments in terms of traces of Hecke operators for certain con ...

Wiley2017

SETS OF p-UNIQUENESS ON NONCOMMUTATIVE LOCALLY COMPACT GROUPS

Antoine Derighetti

We prove that a closed subgroup H of a locally compact group G is a set of p-uniqueness (1 < p < infinity) if and only if H is locally negligible. We also obtain the inverse projection theorem for sets of p-uniqueness. ...

Ars Polona-Ruch2017

Endo-trivial modules: a reduction to p'-central extensions

Jacques Thévenaz, Caroline Lassueur

We examine how, in prime characteristic p, the group of endotrivial modules of a finite group G and the group of endotrivial modules of a quotient of G modulo a normal subgroup of order prime to p are related. There is always an inflation map, but examples ...

2017

Injection Theorem For Local Ditkin Sets

Antoine Derighetti

For Figa-Talamanca-Herz algebras A(p)(G), 1 < p < infinity, of a locally compact group G and a closed subgroup H of G, we prove an injection theorem for local Ditkin sets. ...

Tusi Mathematical Research Group2016

Secure transmission using an untrusted relay with scaled compute-and-forward

Michael Christoph Gastpar, Jasper Goseling

A two-hop channel is considered, in which the source wants to send information to the destination while keeping the information confidential from the relay. A novel lattice chain and compute-and-forward based scheme is proposed in which the destination pro ...

IEEE2015

Small Spectral Radius And Percolation Constants On Non-Amenable Cayley Graphs

Motivated by the Benjamini-Schramm non-unicity of percolation conjecture we study the following question. For a given finitely generated nonamenable group Gamma, does there exist a generating set S such that the Cayley graph (Gamma, S), without loops and m ...

American Mathematical Society (AMS)2015

Subgroups Of Simple Algebraic Groups Containing Regular Tori, And Irreducible Representations With Multiplicity 1 Non-Zero Weights

Donna Testerman

Our main goal is to determine, under certain restrictions, the maximal closed connected subgroups of simple linear algebraic groups containing a regular torus. We call a torus regular if its centralizer is abelian. We also obtain some results of independen ...

Springer Verlag2015

Homogeneous number of free generators

We address two questions of Simon Thomas. First, we show that for any n >= 3 one can find a four-generated free subgroup of SLn (Z) which is profinitely dense. More generally, we show that an arithmetic group Gamma that admits the congruence subgroup prope ...

Walter De Gruyter Gmbh2014

Relative amenability

Nicolas Monod

We introduce a relative fixed point property for subgroups of a locally compact group, which we call relative amenability. It is a priori weaker than amenability. We establish equivalent conditions, related among others to a problem studied by Reiter in 19 ...

European Mathematical Soc2014

Counting conjugacy classes of cyclic subgroups for fusion systems

Sejong Park

Thévenaz [6] made an interesting observation that the number of conjugacy classes of cyclic subgroups in a finite group G is equal to the rank of the matrix of the numbers of double cosets in G. We give another proof of this fact and present a fusion syste ...

Walter de Gruyter2014

Finite metacyclic groups as active sums of cyclic subgroups

Nadia Romero Romero

The notion of active sum provides an analogue for groups of what the direct sum is for abelian groups. One natural question then is which groups are the active sum of a family of cyclic subgroups. Many groups have been found to give a positive answer to th ...

Elsevier2014

A sieve algorithm based on overlattices

In this paper, we present a heuristic algorithm for solving exact, as well as approximate, shortest vector and closest vector problems on lattices. The algorithm can be seen as a modified sieving algorithm for which the vectors of the intermediate sets lie ...

Cambridge Univ Press2014

Irreducibility In Algebraic Groups And Regular Unipotent Elements

Donna Testerman

We study (connected) reductive subgroups G of a reductive algebraic group H, where G contains a regular unipotent element of H. The main result states that G cannot lie in a proper parabolic subgroup of H. This result is new even in the classical case H = ...

American Mathematical Society (AMS)2013

Publications associées (27)

Tusi Mathematical Research Group2016

Secure transmission using an untrusted relay with scaled compute-and-forward

Michael Christoph Gastpar, Jasper Goseling

IEEE2015

Small Spectral Radius And Percolation Constants On Non-Amenable Cayley Graphs

American Mathematical Society (AMS)2015

Subgroups Of Simple Algebraic Groups Containing Regular Tori, And Irreducible Representations With Multiplicity 1 Non-Zero Weights

Donna Testerman

Springer Verlag2015