Results 11 to 20 of about 185 (137)

On the Euler characteristic of S$S$‐arithmetic groups

Journal of the London Mathematical Society, Volume 113, Issue 3, March 2026.
Abstract We show that the sign of the Euler characteristic of an S$S$‐arithmetic subgroup of a simple algebraic group depends on the S$S$‐congruence completion only, except possibly in type 6D4${}^6 D_4$. Consequently, the sign is a profinite invariant for such S$S$‐arithmetic groups with the congruence subgroup property. This generalizes previous work
Holger Kammeyer, Giada Serafini
wiley   +1 more source

Local Cohomology of Modules of Covariants

Advances in Mathematics, 1999
Let \(G\) be a connected reductive algebraic group and \(U\) an irreducible finite dimensional representation of \(G\) and \(S\) the simple roots of \(G\). Then \(G\) acts on the polynomial ring \(R=SU\) associated to \(U\), and \(R^G\) is Cohen-Macaulay by the Hochster-Robert theorem. A conjecture of Stanley [proved partially by the author: \textit{M.
openaire   +2 more sources

Local equivalence and refinements of Rasmussen's s‐invariant

Journal of Topology, Volume 19, Issue 1, March 2026.
Abstract Inspired by the notions of local equivalence in monopole and Heegaard Floer homology, we introduce a version of local equivalence that combines odd Khovanov homology with equivariant even Khovanov homology into an algebraic package called a local even–odd (LEO) triple.
Nathan M. Dunfield, Robert Lipshitz, Dirk Schütz   +2 more
wiley   +1 more source

Cohomological dimension and top local cohomology modules

Rocky Mountain Journal of Mathematics, 2019
Let \(R\) be a commutative Noetherian ring with identity. Let \(I\) be an ideal of \(R\) and \(M\) a finitely generated \(R\)-module. The authors prove some interesting results concerning the notion of cohomological dimension. The \textit{cohomological dimension} of \(M\) with respect to \(I\) is defined as \[ \text{cd}(I,M):=\sup\{i\in \mathbb{N}_0 ...
Erdoğdu, Vahap, Yıldırım, Tuğba
openaire   +2 more sources

Obstructions to homotopy invariance of loop coproduct via parameterized fixed‐point theory

Journal of Topology, Volume 19, Issue 1, March 2026.
Abstract Given f:M→N$f:M \rightarrow N$ a homotopy equivalence of compact manifolds with boundary, we use a construction of Geoghegan and Nicas to define its Reidemeister trace [T]∈π1st(LN,N)$[T] \in \pi _1^{st}(\mathcal {L}N, N)$. We realize the Goresky–Hingston coproduct as a map of spectra, and show that the failure of f$f$ to entwine the spectral ...
Lea Kenigsberg, Noah Porcelli
wiley   +1 more source

Rigidity of anti‐de Sitter (2+1)‐spacetimes with convex boundary near the Fuchsian locus

Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.
Abstract We prove that globally hyperbolic compact anti‐de Sitter (2+1)‐spacetimes with a strictly convex spacelike boundary that is either smooth or polyhedral and whose holonomy is close to Fuchsian are determined by the induced metric on the boundary.
Roman Prosanov, Jean‐Marc Schlenker
wiley   +1 more source

Artinianness of formal local cohomology modules [PDF]

Commentationes Mathematicae Universitatis Carolinae, 2019
Summary: Let \(\mathfrak{a}\) be an ideal of Noetherian local ring \((R,\mathfrak{m})\) and \(M\) a finitely generated \(R\)-module of dimension \(d\). In this paper we investigate the Artinianness of formal local cohomology modules under certain conditions on the local cohomology modules with respect to \(\mathfrak{m}\).
openaire   +1 more source

General formal local cohomology modules [PDF]

Algebra and Discrete Mathematics, 2020
Let (R,m) be a local ring, Φ a system of ideals of R and M a finitely generated R-module. In this paper, we define and study general formal local cohomology modules. We denote the ith general formal local cohomology module M with respect to Φ by FiΦ(M) and we investigate some finiteness and Artinianness properties of general formal local cohomology ...
openaire   +3 more sources

The versal deformation of small resolutions of conic bundles over P1×P1${\mathbb {P}}^1\times {\mathbb {P}}^1$ with two sections blown down

Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.
Abstract Twistor spaces are certain compact complex three‐folds with an additional real fibre bundle structure. We focus here on twistor spaces over P2#P2#P2${\mathbb {P}}^2\#{\mathbb {P}}^2\#{\mathbb {P}}^2$. Such spaces are either small resolutions of double solids or they can be described as modifications of conic bundles.
Bernd Kreußler, Jan Stevens
wiley   +1 more source

F‐purity of binomial edge ideals

Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.
Abstract In 2012, Matsuda introduced the class of weakly closed graphs and investigated when binomial edge ideals are F‐pure. He proved that weakly closed binomial edge ideals are F‐pure whenever the base field has positive characteristic. He conjectured that: (i) when the base field has characteristic 2, every F‐pure binomial edge ideal comes from a ...
Adam LaClair, Jason McCullough
wiley   +1 more source