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Huayi Chen introduces the notion of an approximable graded algebra, which he uses to prove a Fujita-type theorem in the arithmetic setting, and asked if any such algebra is the graded ring of a big line bundle on a projective variety. This…

Algebraic Geometry · Mathematics 2026-05-27 Catriona Maclean

The rational homology group of the order complex of non-even partitions of a finite set is calculated. A twisted version of the Goresky-MacPherson approach to similar homology calculations is proposed.

Combinatorics · Mathematics 2018-07-17 Victor A. Vassiliev

We find an explicit form of the inverse isomorphism from Shapiro's lemma in terms of inhomogeneous cocycles and apply it to construct special nonsplit coverings of groups with a unique conjugacy class of involutions.

Group Theory · Mathematics 2024-10-23 Andrei V. Zavarnitsine

Consider the family of automorphic representations on a unitary group with cohomological factor $\pi_0$ at infinity and given split level. We compute statistics of this family as the level goes to infinity. For unramified unitary groups and…

Number Theory · Mathematics 2024-10-23 Rahul Dalal , Mathilde Gerbelli-Gauthier

The superform construction of supersymmetric invariants, which consists of integrating the top component of a closed superform over spacetime, is reviewed. The cohomological methods necessary for the analysis of closed superforms are…

High Energy Physics - Theory · Physics 2011-03-28 N. Berkovits , P. S. Howe

There are different notions of homology and cohomology that can be defined for a group with an action of another group by group automorphisms. In this paper we address three natural questions that arise in this context. Namely, the relation…

K-Theory and Homology · Mathematics 2020-07-14 Carlos Aquino , Rolando Jimenez , Martin Mijangos , Quitzeh Morales Meléndez

We prove that the cohomology of semi-simple Lie groups admits boundary values, which are measurable cocycles on the Furstenberg boundary. This generalises known invariants such as the Maslov index on Shilov boundaries, the Euler class on…

Group Theory · Mathematics 2020-12-01 Nicolas Monod

We construct some new cohomology theories for topological groups and Lie groups and study some of its basic properties. For example, we introduce a cohomology theory based on measurable cochains which are continuous in a neighbourhood of…

General Topology · Mathematics 2010-09-24 Arati S. Khedekar , C. S. Rajan

We develop a general structure theory for compact homogeneous Riemannian manifolds in relation to the co-index of symmetry. We will then use these results to classify irreducible, simply connected, compact homogeneous Riemannian manifolds…

Differential Geometry · Mathematics 2013-12-23 Jurgen Berndt , Carlos Olmos , Silvio Reggiani

Finite dimensional subspaces spanned by exponential functions in the space of square integrable functions on a finite interval of the real line are considered. Their limiting positions are studied and described in terms of expo-polynomials.

Functional Analysis · Mathematics 2014-10-28 Ruslan Sharipov

In this paper, we study Lie-Rinehart cohomology for quotients of singularities by finite groups, and interpret these cohomology groups in terms of integrable connection on modules.

Algebraic Geometry · Mathematics 2017-04-19 Eivind Eriksen , Trond S. Gustavsen

We investigate space curves with large cohomology. To this end we introduce curves of subextremal type. This class includes all subextremal curves. Based on geometric and numerical characterizations of curves of subextremal type, we show…

Algebraic Geometry · Mathematics 2007-05-23 Nadia Chiarli , Silvio Greco , Uwe Nagel

For Hamiltonian circle actions on compact, connected, four-dimensional manifolds, we give a generators and relations description for the even part of the equivariant cohomology, as an algebra over the equivariant cohomology of a point. This…

Symplectic Geometry · Mathematics 2025-08-13 Tara Holm , Liat Kessler

An integer-valued fixed point index for compositions of acyclic multivalued maps is constructed. This integer-valued fixed point index has the properties: additivity, homotoy invariance, normalization, commutativity, multiplicativity. The…

General Topology · Mathematics 2007-05-23 E. G. Sklyarenko , G. Skordev

The concept of assignments was introduced in [GGK99] as a method for extracting geometric information about group actions on manifolds from combinatorial data encoded in the infinitesimal orbit-type stratification. In this paper we will…

Algebraic Topology · Mathematics 2013-04-19 Victor Guillemin , Silvia Sabatini , Catalin Zara

In this paper, we investigate certain graded-commutative rings which are related to the reciprocal plane compactification of the coordinate ring of a complement of a hyperplane arrangement. We give a presentation of these rings by…

Algebraic Topology · Mathematics 2021-05-20 Sophie Kriz

We generalize the idea of cofinite groups, due to B. Hartley. First we define cofinite spaces in general. Then, as a special situation, we study cofinite graphs and their uniform completions. The idea of constructing a cofinite graph starts…

General Topology · Mathematics 2016-02-08 Amrita Acharyya , Jon M. Corson , Bikash Das

We generalize and complete some of Maxim's recent results on Alexander invariants of a polynomial transversal to the hyperplane at infinity. Roughly speaking, and surprisingly, such a polynomial behaves both topologically and algebraically…

Algebraic Geometry · Mathematics 2007-05-23 Alexandru Dimca , Anatoly Libgober

With a view towards applications in the theory of infinite-dimensional representations of finite-dimensional Lie supergroups, we introduce a new category of supermanifolds. In this category, supermanifolds of `maps' and `fields' (fibre…

Differential Geometry · Mathematics 2011-09-15 Alexander Alldridge

This paper is an expository account of the theory of stable infinity categories. We prove that the homotopy category of a stable infinity category is triangulated, and that the collection of stable infinity categories is closed under a…

Category Theory · Mathematics 2009-05-08 Jacob Lurie