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Related papers: Euler characteristic on noncommutative polyballs

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The Euler characteristic of a very affine variety encodes the algebraic complexity of solving likelihood (or scattering) equations on this variety. We study this quantity for the Grassmannian with $d$ hyperplane sections removed. We provide…

Algebraic Geometry · Mathematics 2026-04-08 Elia Mazzucchelli , Dmitrii Pavlov , Kexin Wang

The notion of the orbifold Euler characteristic came from physics at the end of 80's. There were defined higher order versions of the orbifold Euler characteristic and generalized ("motivic") versions of them. In a previous paper the…

Algebraic Geometry · Mathematics 2019-06-06 S. M. Gusein-Zade , I. Luengo , A. Melle-Hernández

In a 1967 paper, Banchoff stated that a certain type of polyhedral curvature, that applies to all finite polyhedra, was zero at all vertices of an odd-dimensional polyhedral manifold; one then obtains an elementary proof that…

Geometric Topology · Mathematics 2007-05-23 Ethan D. Bloch

We give explicit computations of the $\Gamma$-Euler characteristic of several families of orbit space definable translation groupoids. These include the translation groupoids associated to finite-dimensional linear representations of the…

Algebraic Topology · Mathematics 2025-08-27 Carla Farsi , Hannah Mobley , Christopher Seaton

The structure of subspaces of a Hilbert space that are invariant under unitary representations of a discrete group is related to a notion of Hilbert modules endowed with inner products taking values in spaces of unbounded operators. A…

Functional Analysis · Mathematics 2015-07-01 Davide Barbieri , Eugenio Hernández , Victoria Paternostro

Two of the pillars of combinatorics are the notion of choosing an arbitrary subset of a set with $n$ elements (which can be done in $2^n$ ways), and the notion of choosing a $k$-element subset of a set with $n$ elements (which can be done…

Combinatorics · Mathematics 2007-05-23 James Propp

Let p be a prime number, G a finite group, and A a finite group acting on G. The Brown poset of nonidentity p-subgroups of G is then an A-poset. We investigate the equivariant subposet and the equivariant Euler characteristics and establish…

Group Theory · Mathematics 2016-02-22 Jesper M. Møller

We construct smooth axisymmetric-with-swirl initial data in a periodic cylinder for which the three-dimensional incompressible Euler evolution develops a finite-time boundary singularity. The construction is carried out in the dynamically…

Analysis of PDEs · Mathematics 2026-05-07 Rishad Shahmurov

A quandle is an algebraic system whose axioms generalize the algebraic structure of the point symmetries of symmetric spaces. In this paper, we give a definition of Euler characteristics for quandles. In particular, the quandle Euler…

Geometric Topology · Mathematics 2024-11-14 Ryoya Kai , Hiroshi Tamaru

This note describes sharp Milnor--Wood inequalities for the Euler number of flat oriented vector bundles over closed Riemannian manifolds locally isometric to products of hyperbolic planes. One consequence is that such manifolds do not…

Geometric Topology · Mathematics 2008-04-15 Michelle Bucher , Tsachik Gelander

We introduce the notion of characteristic functions for commuting tuples of hypercontractions on Hilbert spaces, as a generalization of the notion of Sz.-Nagy and Foias characteristic functions of contractions. We present an explicit method…

Functional Analysis · Mathematics 2019-05-22 Monojit Bhattacharjee , B. Krishna Das , Jaydeb Sarkar

To each finite-dimensional operator space $E$ is associated a commutative operator algebra $UC(E)$, so that $E$ embeds completely isometrically in $UC(E)$ and any completely contractive map from $E$ to bounded operators on Hilbert space…

Functional Analysis · Mathematics 2010-10-01 Michael T. Jury

In this article, the cohomology of the arithmetic group $\mathrm{Sp}_4(\mathbb{Z})$ with coefficients in any finite dimensional highest weight representation $\mathcal{M}_\lambda$ have been studied. Euler characteristic with coefficients in…

Number Theory · Mathematics 2021-07-15 Jitendra Bajpai , Ivan Horozov , Matias Moya Giusti

We characterize the domain of the realization of the linear parabolic operator Gu := u_t + L(t)u (where, for each real t, L(t) is an Ornstein-Uhlenbeck operator), in L^2 spaces with respect to a suitable measure, that is invariant for the…

Analysis of PDEs · Mathematics 2014-02-26 Matthias Geissert , Alessandra Lunardi

The use of unitary invariant subspaces of a Hilbert space $\mathcal{H}$ is nowadays a recognized fact in the treatment of sampling problems. Indeed, shift-invariant subspaces of $L^2(\mathbb{R})$ and also periodic extensions of finite…

Functional Analysis · Mathematics 2016-06-29 Antonio G. García , Alberto Ibort , María J. Muñoz-Bouzo

In this paper, first we prove the existence of invariant vector field on a homogeneous Finsler space with infinite series $(\alpha, \beta)$-metric and exponential metric. Next, we deduce an explicit formula for the the $S$-curvature of…

Differential Geometry · Mathematics 2017-12-29 Gauree Shanker , Kirandeep Kaur

We present an exact formula for moments and cumulants of several real compound Wishart matrices in terms of an Euler characteristic expansion, similar to the genus expansion for complex random matrices. We consider their asymptotic values…

Probability · Mathematics 2015-03-25 C. Emily I. Redelmeier

We investigate periodic diffeomorphisms of non-compact aspherical manifolds (and orbifolds) and describe a class of spaces that have no homotopically trivial periodic diffeomorphisms. Prominent examples are moduli spaces of curves and…

Geometric Topology · Mathematics 2015-01-14 Grigori Avramidi

Generating functions for the number of commuting m-tuples in the symmetric groups are obtained. We define a natural sequence of ``orbifold Euler characteristics'' for a finite group G acting on a manifold X. Our definition generalizes the…

Combinatorics · Mathematics 2007-05-23 Jim Bryan , Jason Fulman

Given a perverse sheaf on the moduli stack of principally polarized abelian varieties or the moduli stack of smooth curves with n marked points over a field of characteristic zero, we prove that the (orbifold) Euler characteristic is…

Algebraic Geometry · Mathematics 2025-12-08 Donu Arapura , Deepam Patel