Results 1 to 10 of about 45,702 (171)

Hyperbolic localization of intersection cohomology [PDF]

Transformation Groups, 2003
For a normal variety X defined over an algebraically closed field with an action of the multiplicative group G_m, we consider the ``hyperbolic localization'' functor from D^b(X) to D^b(X^T), which localizes using closed supports in the directions flowing into the fixed points, and compact supports in the directions flowing out.
Tom Braden
openaire   +5 more sources

Postulation of schemes of length at most 4 on surfaces

Bulletin of the London Mathematical Society, Volume 58, Issue 3, March 2026.
Abstract In this paper, we address the postulation problem of zero‐dimensional schemes of length at most 4 on a surface. We prove some general results and then we focus on the case of P2$\mathbb {P}^2$, P1×P1$\mathbb {P}^1\times \mathbb {P}^1$ and Hirzebruch surfaces. In particular, we prove that except for few well‐known exceptions, a general union of
Edoardo Ballico, Stefano Canino
wiley   +1 more source

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

Global Intersection Cohomology of Quasimaps' Spaces

, 1997
Let $C$ be a smooth projective curve of genus 0. Let $\CB$ be the variety of complete flags in an $n$-dimensional vector space $V$. Given an $(n-1)$-tuple $ \in\BN[I]$ of positive integers one can consider the space $\CQ_ $ of algebraic maps of degree $ $ from $C$ to $\CB$. This space admits some remarkable compactifications $\CQ^D_ $ (Quasimaps), $
Finkelberg, Michael, Kuznetsov, Alexander   +1 more
openaire   +2 more sources

Intersection cohomology of hypertoric varieties

Journal of Algebraic Geometry, 2006
A hypertoric variety is a quaternionic analogue of a toric variety. Just as the topology of toric varieties is closely related to the combinatorics of polytopes, the topology of hypertoric varieties interacts richly with the combinatorics of hyperplane arrangements and matroids.
Proudfoot, Nicholas, Webster, Benjamin
openaire   +2 more sources

Harmonic maps to the circle with higher dimensional singular set

Proceedings of the London Mathematical Society, Volume 132, Issue 3, March 2026.
Abstract In a closed, oriented ambient manifold (Mn,g)$(M^n,g)$ we consider the problem of finding S1$\mathbb {S}^1$‐valued harmonic maps with prescribed singular set. We show that the boundary of any oriented (n−1)$(n-1)$‐submanifold can be realised as the singular set of an S1$\mathbb {S}^1$‐valued map, which is classically harmonic away from the ...
Marco Badran
wiley   +1 more source

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

A physical basis for cosmological correlators from cuts

Journal of High Energy Physics
Significant progress has been made in our understanding of the analytic structure of FRW wavefunction coefficients, facilitated by the development of efficient algorithms to derive the differential equations they satisfy.
Shounak De, Andrzej Pokraka
doaj   +1 more source

Natural operations in Intersection Cohomology

, 2020
Eilenberg-MacLane spaces, that classify the singular cohomology groups of topological spaces, admit natural constructions in the framework of simplicial sets. The existence of similar spaces for the intersection cohomology groups of a stratified space is a long-standing open problem asked by M. Goresky and R. MacPherson.
Chataur, David, Tanré, Daniel
openaire   +2 more sources

WDVV‐based recursion for open Gromov–Witten invariants

Journal of Topology, Volume 19, Issue 1, March 2026.
Abstract We give a computability result for open Gromov–Witten invariants based on open Witten–Dijkgraaf–Verlinde–Verlinde (WDVV) equations. This is analogous to the result of Kontsevich–Manin for closed Gromov–Witten invariants. For greater generality, we base the argument on a formal object, the Frobenius superpotential, that generalizes several ...
Roi Blumberg, Sara B. Tukachinsky
wiley   +1 more source