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Related papers: Descente pour les n-champs (Descent for n-stacks)

200 papers

We establish convergence theorems for Riemannian stochastic gradient descents in which the underlying probability spaces vary from iteration to iteration. As applications, we deduce convergence results for Riemannian stochastic gradient…

Optimization and Control · Mathematics 2026-04-21 Hao Wu

We define the continuous modeling property for first-order structures and show that a first-order structure has the continuous modelling property if and only if its age has the embedding Ramsey property. We use generalized indiscernible…

Logic · Mathematics 2024-05-31 Adrián Portillo Fernández

In arXiv:0805.0157v5, the authors define a class of derived stacks, called "perfect stacks" and show that for this class the categories of quasi-coherent sheaves satisfy a categorical K\"unneth formula. Motivated to extend their results to…

Algebraic Geometry · Mathematics 2025-07-14 Youshua Kesting

We propose a simple, scalable, and fast gradient descent algorithm to optimize a nonconvex objective for the rank minimization problem and a closely related family of semidefinite programs. With $O(r^3 \kappa^2 n \log n)$ random…

Machine Learning · Statistics 2016-03-25 Qinqing Zheng , John Lafferty

We generalize the notion of a crossed module of groups to that of a crossed module of racks. We investigate the relation to categorified racks, namely strict 2-racks, and trunk-like objects in the category of racks, generalizing the…

Quantum Algebra · Mathematics 2014-04-02 Alissa S. Crans , Friedrich Wagemann

We develop a unified sampling theory based on sheaves and show that the Shannon-Nyquist theorem is a cohomological consequence of an exact sequence of sheaves. Our theory indicates that there are additional cohomological obstructions for…

Algebraic Topology · Mathematics 2013-07-30 Michael Robinson

Most existing analyses of (stochastic) gradient descent rely on the condition that for $L$-smooth costs, the step size is less than $2/L$. However, many works have observed that in machine learning applications step sizes often do not…

Optimization and Control · Mathematics 2022-06-10 Kwangjun Ahn , Jingzhao Zhang , Suvrit Sra

In this article, we construct a $2$-category of Lagrangians in a fixed shifted symplectic derived stack S. The objects and morphisms are all given by Lagrangians living on various fiber products. A special case of this gives a $2$-category…

Symplectic Geometry · Mathematics 2022-10-12 Lino Amorim , Oren Ben-Bassat

We define stacks of uniform cyclic covers of Brauer-Severi schemes, proving that they can be realized as quotient stacks of open subsets of representations, and compute the Picard group for the open substacks parametrizing smooth uniform…

Algebraic Geometry · Mathematics 2007-05-23 Alessandro Arsie , Angelo Vistoli

Let R be a discrete valuation ring with algebraically closed residue field, and consider a smooth curve CK over the field of fractions K. For any positive integer r prime to the residual characteristic, we consider the finite K-group scheme…

Algebraic Geometry · Mathematics 2007-05-23 Alessandro Chiodo

Using a result of Gessel and Reutenauer, we find a simple formula for the number of cyclic permutations with a given descent set, by expressing it in terms of ordinary descent numbers (i.e., those counting all permutations with a given…

Combinatorics · Mathematics 2019-07-16 Sergi Elizalde , Justin M. Troyka

We study the circumstances under which one can reconstruct a stack from its associated functor of isomorphism classes. This is possible surprisingly often: we show that many of the standard examples of moduli stacks are determined by their…

Algebraic Geometry · Mathematics 2018-06-18 Max Lieblich , Brian Osserman

We investigate a possible theory of higher Fukaya categories associated to $n$-shifted symplectic stacks, where $n \geq 0$. We consider two paradigmatic cases, the shifted cotangent stack of a smooth manifold and the coadjoint stack of a…

Symplectic Geometry · Mathematics 2025-04-01 James Pascaleff , Nicolò Sibilla

We introduce the theory of unipotent morphisms of algebraic stacks and prove a surprising local to global principle for a class of vector bundles. Two sample applications of our methods are the following: (1) a unipotent analogue of…

Algebraic Geometry · Mathematics 2026-05-06 Daniel Bragg , Jack Hall , Siddharth Mathur

Graph vertex embeddings based on random walks have become increasingly influential in recent years, showing good performance in several tasks as they efficiently transform a graph into a more computationally digestible format while…

Machine Learning · Statistics 2021-07-22 Dominik Kloepfer , Angelica I. Aviles-Rivero , Daniel Heydecker

In this work, we explore proof theoretical connections between sequent, nested and labelled calculi. In particular, we show a general algorithm for transforming a class of nested systems into sequent calculus systems, passing through linear…

Logic in Computer Science · Computer Science 2018-02-15 Elaine Pimentel

We define the notion of 1-affineness for a prestack, and prove an array of results that establish 1-affineness of certain types of prestacks.

Algebraic Geometry · Mathematics 2014-08-12 Dennis Gaitsgory

The cornerstone underpinning deep learning is the guarantee that gradient descent on an objective converges to local minima. Unfortunately, this guarantee fails in settings, such as generative adversarial nets, where there are multiple…

Machine Learning · Computer Science 2018-06-07 David Balduzzi , Sebastien Racaniere , James Martens , Jakob Foerster , Karl Tuyls , Thore Graepel

We develop a formalism of cohomological descent encoding adelic points and obstructions to local-global principle on algebraic stacks. As an application, by constructing new obstructions using the formalism, we obtain some comparison…

Algebraic Geometry · Mathematics 2026-03-25 Chang Lv

Some aspects of basic category theory are developed in a finitely complete category $\C$, endowed with two factorization systems which determine the same discrete objects and are linked by a simple reciprocal stability law. Resting on this…

Category Theory · Mathematics 2008-02-06 Claudio Pisani