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We present an algorithm for approximating linear categories of partitions (of sets). We report on concrete computer experiments based on this algorithm which we used to obtain first examples of so-called non-easy linear categories of…

Category Theory · Mathematics 2024-02-07 Daniel Gromada , Moritz Weber

Several important cases of vector bundles with extra structure (such as Higgs bundles and triples) may be regarded as examples of twisted representations of a finite quiver in the category of sheaves of modules on a variety/manifold/ringed…

Algebraic Geometry · Mathematics 2007-05-23 Peter B. Gothen , Alastair D. King

We describe the Macaulay2 package TateOnProducts and its capabilities, which include computing cohomology tables and Beilinson monads of sheaves on products of projective spaces and the derived category pushForward of a sheaf under a…

Algebraic Geometry · Mathematics 2019-05-27 Daniel Erman , David Eisenbud , Frank-Olaf Schreyer

Shapley-related techniques have gained attention as both global and local interpretation tools because of their desirable properties. However, their computation using conditional expectations is computationally expensive. Approximation…

Machine Learning · Statistics 2022-07-13 Zhipu Zhou , Jie Chen , Linwei Hu

We present an algorithm to compute the torsion component $\mathrm{Pic}^\tau X$ of the Picard scheme of a smooth projective variety $X$ over a field $k$. Specifically, we describe $\mathrm{Pic}^\tau X$ as a closed subscheme of a projective…

Algebraic Geometry · Mathematics 2026-01-26 Hyuk Jun Kweon , Madhavan Venkatesh

We describe an algorithm for fast multiplication of skew polynomials. It is based on fast modular multiplication of such skew polynomials, for which we give an algorithm relying on evaluation and interpolation on normal bases. Our…

Symbolic Computation · Computer Science 2017-02-07 Xavier Caruso , Jérémy Le Borgne

The main purpose of this paper is to develop new algorithms for computing invariant rings in a general setting. This includes invariants of nonreductive groups but also of groups acting on algebras over certain rings. In particular, we…

Commutative Algebra · Mathematics 2014-04-01 Gregor Kemper

Complex braid groups are the natural generalizations of braid groups associated to arbitrary (finite) complex reflection groups. We investigate several methods for computing the homology of these groups. In particular, we get the Poincar\'e…

Algebraic Topology · Mathematics 2010-11-22 Filippo Callegaro , Ivan Marin

The topic of this thesis is the development of a versatile and geometrically motivated differential calculus on non-commutative or quantum spaces, providing powerful but easy-to-use mathematical tools for applications in physics and related…

High Energy Physics - Theory · Physics 2008-02-03 Peter Schupp

We introduce an ensemble learning scheme for community detection in complex networks. The scheme uses a Machine Learning algorithmic paradigm we call Extremal Ensemble Learning. It uses iterative extremal updating of an ensemble of network…

Physics and Society · Physics 2019-10-04 Jiahao Guo , Pramesh Singh , Kevin E. Bassler

This paper considers the problem of distributed estimation in an incremental network when the measurements taken by the node follow a widely linear model. The proposed algorithm which we refer to it as incremental augmented affine…

Distributed, Parallel, and Cluster Computing · Computer Science 2014-12-19 Azam Khalili , Wael M. Bazzi , Amir Rastegarnia

We find new constructions of infinite families of skew Hadamard difference sets in elementary abelian groups under the assumption of the existence of cyclotomic strongly regular graphs. Our construction is based on choosing cyclotomic…

Combinatorics · Mathematics 2012-08-29 Koji Momihara

The Witt group of a smooth curve over a real closed field is explicitely calculated. The method uses a comparison theorem between the graded Witt group and the etale cohomology groups. In the second part of the paper, the torsion Picard…

Algebraic Geometry · Mathematics 2007-05-23 J-P. Monnier

We provide a general method for computing rational Chow rings of moduli of smooth complete intersections. We specialize this result in different ways: to compute the integral Picard group of the associated stack ; to obtain an explicit…

Algebraic Geometry · Mathematics 2022-01-19 Andrea Di Lorenzo

Stable computational algorithms for the approximate solution of the Cauchy problem for nonstationary problems are based on implicit time approximations. Computational costs for boundary value problems for systems of coupled multidimensional…

Numerical Analysis · Mathematics 2024-03-28 P. N. Vabishchevich

In 1990, D.Snow proposed an effective algorithm for computing the orbits of finite Weyl groups. Snow's algorithm is designed for computation of weights, $W$-orbits and elements of the Weyl group. An extension of Snow's algorithm is…

Representation Theory · Mathematics 2023-11-21 Rafael Stekolshchik

We present generating functions for extensions of multiplicative invariants of wreath symmetric products of orbifolds presented as the quotient by the locally free action of a compact, connected Lie group in terms of orbifold sector…

Algebraic Topology · Mathematics 2019-02-20 Carla Farsi , Christopher Seaton

We propose an explicit and practical algorithm for computing Galois conjugates and irreducible polynomials for special values of modular functions evaluated at CM points associated with imaginary quadratic orders. Our approach builds upon…

Number Theory · Mathematics 2025-06-18 Ja Kyung Koo , Dong Hwa Shin , Dong Sung Yoon

We introduce equivariant Chow-Witt groups in order to define Chow-Witt groups of quotient stacks. We compute the Chow-Witt ring of the moduli stack of stable (resp. smooth) elliptic curves, providing a geometric interpretation of the new…

Algebraic Geometry · Mathematics 2023-05-11 Andrea Di Lorenzo , Lorenzo Mantovani

Deep Ensembles are a simple, reliable, and effective method of improving both the predictive performance and uncertainty estimates of deep learning approaches. However, they are widely criticised as being computationally expensive, due to…

Machine Learning · Computer Science 2023-10-10 Guoxuan Xia , Christos-Savvas Bouganis