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Let $A$ be a noetherian connected graded algebra. We introduce and study homological invariants that are weighted sums of the homological and internal degrees of cochain complexes of graded $A$-modules, providing weighted versions of…

Rings and Algebras · Mathematics 2023-06-12 Ellen Kirkman , Robert Won , James J. Zhang

Refined stability estimates are derived for classical mixed problems. The novel emphasis is on the importance of semi norms on data functionals, inspired by recent progress on pressure-robust discretizations for the incompressible…

Numerical Analysis · Mathematics 2025-06-16 Nicolas Gauger , Alexander Linke , Christian Merdon

Following Artin and Zhang's formulation of noncommutative projective geometry, we classify up a family of skew polynomial quadratic algebras up to graded Morita equivalence and their corresponding noncommutative projective spaces up to…

Rings and Algebras · Mathematics 2015-03-13 Jorge Vitoria

Non-convex optimization problems often arise from probabilistic modeling, such as estimation of posterior distributions. Non-convexity makes the problems intractable, and poses various obstacles for us to design efficient algorithms. In…

Machine Learning · Computer Science 2013-12-18 Khoat Than , Tu Bao Ho

New relations among the genus-zero Gromov-Witten invariants of a complex projective manifold $X$ are exhibited. When the cohomology of $X$ is generated by divisor classes and classes ``with vanishing one-point invariants,'' the relations…

Algebraic Geometry · Mathematics 2007-05-23 Aaron Bertram , Holger P. Kley

We introduce a new stable birational invariant, which takes the form of a functor sending a degenerating variety to the homotopy type of a chain complex. Our invariant is a categorification of the motivic volume of Nicaise and Shinder. From…

Algebraic Geometry · Mathematics 2025-03-03 James Hotchkiss , David Stapleton

Parametric projections let analysts embed new points in real time, but input variations from measurement noise or data drift can produce unpredictable shifts in the 2D layout. Whether and where a projection is locally stable remains largely…

Computer Vision and Pattern Recognition · Computer Science 2026-04-24 Frederik L. Dennig , Daniel A. Keim

We introduce a de Rham model for stratified spaces arising from symplectic reduction. It turns out that the reduced symplectic form and its powers give rise to well-defined cohomology classes, even on a singular symplectic quotient.

Symplectic Geometry · Mathematics 2007-05-23 Reyer Sjamaar

We express the rational cohomology of the unordered configuration space of a compact oriented manifold as a representation of its mapping class group in terms of a weight-decomposition of the rational cohomology of the mapping space from…

Algebraic Topology · Mathematics 2021-07-20 Andreas Stavrou

We consider a parametric quasi-variational inequality (QVI) without any convexity assumption. Using the concept of \emph{optimal value function}, we transform the problem into that of solving a nonsmooth system of inequalities. Based on…

Optimization and Control · Mathematics 2024-08-21 Joydeep Dutta , Lahoussine Lafhim , Alain Zemkoho , Shenglong Zhou

In this expository article we give a categorical definition of the integral cohomology ring of a stack. We show that for quotient stacks the categorical cohomology may be identified with equivariant cohomology. Via this identification we…

Algebraic Geometry · Mathematics 2011-08-08 Dan Edidin

We herein propose a variant of the projected inexact Levenberg--Marquardt method (ILMM) for solving constrained nonsmooth equations. Since the orthogonal projection onto the feasible set may be computationally expensive, we propose a local…

Optimization and Control · Mathematics 2021-05-06 Fabiana R. de Oliveira , Fabrícia R. Oliveira

Recent results in geometric invariant theory (GIT) for non-reductive linear algebraic group actions allow us to stratify quotient stacks of the form [X/H], where X is a projective scheme and H is a linear algebraic group with internally…

Algebraic Geometry · Mathematics 2017-11-29 Gergely Bérczi , Victoria Hoskins , Frances Kirwan

We study the existence and regularity of invariant graphs for bundle maps (or bundle correspondences with generating bundle maps motivated by ill-posed differential equations) having some relative partial hyperbolicity on non-trivial and…

Dynamical Systems · Mathematics 2020-10-14 Deliang Chen

A novel family of integrable third order maps is presented. Each map possesses, by construction, a pair of rational invariants and a commuting map from the same class. The 3-dimensional invariant curve is parametrized, in general, by an…

Exactly Solvable and Integrable Systems · Physics 2007-05-23 V. E. Adler

Invariant manifolds are fundamental tools for describing and understanding nonlinear dynamics. In this paper, we present a theory of stable and unstable manifolds for infinite dimensional random dynamical systems generated by a class of…

Dynamical Systems · Mathematics 2019-08-15 Jinqiao Duan , Kening Lu , Bjorn Schmalfuss

We consider operations between two multiplicative, complex orientable cohomology theories. Under suitable hypotheses, we construct a map from unstable to stable operations, left-inverse to the usual map from stable to unstable operations.…

Algebraic Topology · Mathematics 2016-01-20 Andrew Stacey , Sarah Whitehouse

We use Bott periodicity to relate previously defined quantum classes to certain "exotic Chern classes" on $BU$. This provides an interesting computational and theoretical framework for some Gromov-Witten invariants connected with…

Symplectic Geometry · Mathematics 2012-11-21 Yasha Savelyev

We suggest to endow Mumford's GIT quotient scheme with a stack structure, by replacing Proj(-) of the invariant ring with its stack theoretic analogue. We analyse the stacks resulting in this way from classically studied invariant rings,…

Algebraic Geometry · Mathematics 2011-04-27 Martin G. Gulbrandsen

We compute the degree of the variety parametrizing rational ruled surfaces of degree d in the projective space by relating the problem to Gromov-Witten invariants and Quantum cohomology.

Algebraic Geometry · Mathematics 2007-05-23 Cristina Martinez Ramirez