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Related papers: A theorem of Poincar\'e-Hopf type

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We discuss an algorithm computing the push-forward to projective space of several classes associated to a (possibly singular, reducible, nonreduced) projective scheme. For example, the algorithm yields the topological Euler characteristic…

Algebraic Geometry · Mathematics 2012-04-10 Paolo Aluffi

A Hopf monoid (in Joyal's category of species) is an algebraic structure akin to that of a Hopf algebra. We provide a self-contained introduction to the theory of Hopf monoids in the category of species. Combinatorial structures which…

Quantum Algebra · Mathematics 2012-10-12 Marcelo Aguiar , Swapneel Mahajan

We define a notion of a symplectic structure on stratified spaces, and demonstrate that given a symplectic structure on a stratified space $X$ with integral cohomology class, $X$ can be symplectically embedded in some complex projective…

Symplectic Geometry · Mathematics 2023-08-15 Mahan Mj , Balarka Sen

In this survey one discusses the notion of the Poincar\'e series of multi-index filtrations, an alternative approach to the definition, a method of computation of the Poincar\'e series based on the notion of integration with respect to the…

Algebraic Geometry · Mathematics 2015-04-21 A. Campillo , F. Delgado , S. M. Gusein-Zade

The purpose of this paper is to explain why the functor that sends a stratified topological space $S$ to the $\infty$-category of constructible (hyper)sheaves on $S$ with coefficients in a large class of presentable $\infty$categories is…

Algebraic Topology · Mathematics 2022-09-09 Peter J. Haine , Mauro Porta , Jean-Baptiste Teyssier

For an $n$-fold geometrically cyclic branched covering $Y$ of a smooth, projective scheme $X$ branched at a smooth closed subscheme $Z\subset X$ with $n \in k^\times$, we compute the quadratic Euler characteristic of $Y$ in terms of certain…

Algebraic Geometry · Mathematics 2026-05-14 Louisa F. Bröring

We give a sheaf-theoretic version of the universal coefficient theorem.

Commutative Algebra · Mathematics 2024-10-25 Bruno Kahn

We construct certain operations on stable moduli spaces and use them to compare cohomology of moduli spaces of closed manifolds with tangential structure. We obtain isomorphisms in a stable range provided the $p$-adic valuation of the Euler…

Algebraic Topology · Mathematics 2020-03-24 Soren Galatius , Oscar Randal-Williams

If $X$ is a smooth toric variety over an algebraically closed field of positive characteristic and $L$ is an invertible sheaf on $X$, it is known that $F_* L$, the push-forward of $L$ along the Frobenius morphism of $X$, is a direct sum of…

Algebraic Geometry · Mathematics 2013-03-26 Piotr Achinger

We develop a general theory of extensions of flat functors along geometric morphisms of toposes, and apply it to the study of the class of theories whose classifying topos is equivalent to a presheaf topos. As a result, we obtain a…

Category Theory · Mathematics 2014-06-23 Olivia Caramello

We prove a character formula for the Hopf algebra defined in arXiv:1401.5302 that generalizes quantum groups, as well as for the simple modules associated to dominant integral weights defined in arXiv:1403.0846.

Representation Theory · Mathematics 2017-01-11 Tristan Bozec

Let H be a quasi-Hopf algebra, a weak Hopf algebra or a braided Hopf algebra. Let B be an H-bicomodule algebra such that there exists a morphism of H-bicomodule algebras v:H\rightarrow B. Then we can define an object B^{co(H)} which is a…

Quantum Algebra · Mathematics 2013-10-18 Jeroen Dello , Florin Panaite , Freddy Van Oystaeyen , Yinhuo Zhang

In this paper we introduce constructible analogs of the discrete complexity classes $\mathbf{VP}$ and $\mathbf{VNP}$ of sequences of functions. The functions in the new definitions are constructible functions on $\mathbb{R}^n$ or…

Algebraic Geometry · Mathematics 2017-10-09 Saugata Basu

The Grothendieck-Ogg-Shafarevich formula expresses the Euler characteristic of an etale sheaf on a curve in terms of local data. The purpose of this paper is to prove a version of the G-O-S formula which applies to equicharacteristic…

Algebraic Geometry · Mathematics 2009-06-23 Carl A. Miller

A lot of good properties of etale cohomology only hold for torsion coefficients. We use "enlargement of categories" as developed in http://arxiv.org/abs/math.CT/0408177 to define a cohomology theory that inherits the important properties of…

Algebraic Geometry · Mathematics 2007-05-23 Lars Brünjes , Christian Serpé

Given a semisimple Frobenius manifold, we construct a class of integrable deformations of its hierarchy of topological type. We show that these integrable deformations have polynomial tau-structures, and conjecture that for the…

Mathematical Physics · Physics 2025-11-11 Si-Qi Liu , Paolo Rossi , Di Yang , Youjin Zhang

The characteristic cycle of a complex of sheaves on a complex analytic space provides weak information about the complex; essentially, it yields the Euler characteristics of the hypercohomology of normal data to strata. We show how perverse…

Algebraic Geometry · Mathematics 2007-05-23 David B. Massey

We present a uniform theory of constructible sheaves on arbitrary schemes with coefficients in topological or even condensed rings. This is accomplished by defining lisse sheaves to be the dualizable objects in the derived infinity-category…

Algebraic Geometry · Mathematics 2023-05-30 Tamir Hemo , Timo Richarz , Jakob Scholbach

In this work, we present an alternative definition of the Le Roux index, which generalizes the Poincar\'e-Hopf index for non-singular planar flows to the broader setting of Brouwer homeomorphisms. This new approach answers a question raised…

Dynamical Systems · Mathematics 2026-01-23 Nelson Schuback

We present characterizations of braided co-Frobenius Hopf algebras in the braided tensor category of Yetter-Drinfeld modules over a Hopf algebra extending those already known for co-Frobenius Hopf algebras.

Quantum Algebra · Mathematics 2019-11-05 Fiorela Rossi Bertone