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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,742 papers · 148 categories

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14274154 · Jun 202619922001200920172026
48 results for Serre vanishing

The Serre-Swan theorem in differential geometry establishes an equivalence between the category of smooth vector bundles over a smooth compact manifold and the category of finitely generated projective modules over the unital ring of smooth functions. This theorem is here generalized to manifolds of bounded geometry. I…

2013-02-14abs ↗pdf ↗

Study non-vanishing 2\ell^2-Betti numbers for specific groups.

problem Calculating non-vanishing 2\ell^2-Betti numbers for certain groups.
method Using Euler characteristics, higher Kazhdan projections, and Baum-Connes assembly map.
result Non-vanishing calculations for delocalised 2\ell^2-Betti numbers.

We find a presentation of symplectic Steinberg modules and show vanishing cohomology for certain groups.

problem Cohomology vanishing for specific groups and modules.
method Presented a symplectic Steinberg module and used it to prove cohomology vanishing.
result Cohomology of Sp2n(Z)\operatorname{Sp}_{2n}(\mathbb{Z}) vanishes in a specific degree for n2n \geq 2.

Describes the relationship between two spectral sequences and their joint refinement.

problem Computing the cohomology of a group or space using spectral sequences.
method Joint tri-graded refinement of the Leray--Serre and Eilenberg--Moore spectral sequences.
result One of the spectral sequences always degenerates from its second page, and the other satisfies a local-to-global property.

Study on cohomology of SL_n(Z) for n>=3, proving vanishing of certain cohomology groups.

problem Determine the cohomology of SL_n(Z) for n>=3.
method Construct a partial resolution of the Steinberg module to show vanishing of specific cohomology groups.
result Vanishing of codimension-2 rational cohomology group H^{{n \choose 2} -2} for n >= 3.

We prove that the full twist is a Serre functor in the homotopy category of type A Soergel bimodules. As a consequence, we relate the top and bottom Hochschild degrees in Khovanov-Rozansky homology, categorifying a theorem of Kálmán.

2019-02-21abs ↗pdf ↗

We show that for groups acting acylindrically on simplicial trees the KK- and LL-theoretic Farrell-Jones Conjecture relative to the family of subgroups consisting of virtually cyclic subgroups and all subconjugates of vertex stabilisers holds. As an application, for amalgamated free products acting acylindrically on …

2017-04-19abs ↗pdf ↗

It was proved by H. Whitney in 1933 that a Serre fibration of compact metric spaces admits a global section provided every fiber is homeomorphic to the unit interval [0,1]. An extension of the Whitney's theorem to the case when all fibers are homeomorphic to some fixed compact two-dimensional manifold was proved by the…

2009-02-19abs ↗pdf ↗

Consider the middle perversity intersection cohomology groups of various compactifications of a Hermitian locally symmetric space. Rapoport and independently Goresky and MacPherson have conjectured that these groups coincide for the reductive Borel-Serre compactification and the Baily-Borel-Satake compactification. Thi…

2001-12-22abs ↗pdf ↗

The paper studies actions on Bass-Serre trees and identifies new CC^*-simple groups.

problem Investigating actions of fundamental groups on Bass-Serre trees and their CC^*-algebraic properties.
method Analyzing boundary actions of fundamental groups of graphs of groups on their Bass-Serre trees.
result Identification of new families of CC^*-simple groups, including tubular groups and certain graphs of groups.

In this paper, we generalize the notion of Serre fibration to the Morita category of topological groupoids and derive the associated long exact sequence of homotopy groups. We use this results for calculation of homotopy groups of various groupoids, such as the foliation groupoid of a Riemannian foliation.

2011-08-26abs ↗pdf ↗

It was proved by H. Whitney in 1933 that a Serre fibration of compact metric spaces admits a global section provided every fiber is homeomorphic to the unit interval [0,1]. Results of this paper extend Whitney theorem to the case when all fibers are homeomorphic to a given compact two-dimensional manifold.

2009-02-19abs ↗pdf ↗

Given a bundle gerbe on a compact smooth manifold or, more generally, on a compact étale Lie groupoid MM, we show that the corresponding category of gerbe modules, if it is non-trivial, is equivalent to the category of finitely generated projective modules over an Azumaya algebra on MM. This result can be seen as an …

2014-01-13abs ↗pdf ↗

The abstract discusses a spectral sequence for Lie algebroids.

problem The abstract tackles the spectral sequence of Lie algebroids.
method The abstract presents a spectral sequence for Lie algebroids, generalizing classical constructions.
result The spectral sequence converges to Lie algebroid cohomology for wide Lie subalgebroids and to formal Lie algebroid cohomology for Lie subalgebroids over proper submanifolds.

L-modules are a combinatorial analogue of constructible sheaves on the reductive Borel-Serre compactification of a locally symmetric space. We define the micro-support of an L-module; it is a set of irreducible modules for the Levi quotients of the parabolic Q-subgroups associated to the strata. We prove a vanishing th…

2001-12-22abs ↗pdf ↗

The paper develops L2L^2-Hodge theory on almost Kähler manifolds and proves the Hopf conjecture.

problem Proving the Hopf conjecture for almost Kähler manifolds.
method Developed L2L^2-Hodge theory identities and applied them to prove vanishing theorems and refine estimates.
result Proved the Hopf conjecture for compact almost Kähler manifolds with negative sectional curvature.

Oeljeklaus-Toma (OT) manifolds are complex non-Kähler manifolds whose construction arises from specific number fields. In this note, we compute their de Rham cohomology in terms of invariants associated to the background number field. This is done by two distinct approaches, one using invariant cohomology and the other…

2017-11-21abs ↗pdf ↗

Generalizes jet differential bounds and proves asymptotic Serre duality.

problem Bounding the number of linearly independent holomorphic sections of jet bundles.
method Generalizes existing results for invariant jet differentials, proving asymptotic duality.
result Establishes an asymptotic lower bound on the number of sections of jet bundles.

Develops differential K-theory for noncommutative algebras.

problem Creating a differential extension of algebraic K-theory for noncommutative algebras.
method Introduces secondary transgression forms and a differential refinement of the smooth Serre--Swan correspondence.
result Subsumes differential K-theory for smooth manifolds and fits into a noncommutative differential cohomology hexagon diagram.

We study the behaviour of analytic torsion under smooth fibrations. Namely, let F \to E \to^{f} B be a smooth fiber bundle of connected closed oriented smooth manifolds and let VV be a flat vector bundle over EE. Assume that EE and BB come with Riemannian metrics and VV comes with a unimodular (not necessarily fla…

1997-07-10abs ↗pdf ↗

Reduces Lie (bi-)algebroids and Dirac manifolds using constraint vector bundles.

problem Reduction of Lie (bi-)algebroids and Dirac manifolds.
method Introduces constraint manifolds and constraint vector bundles; proves constraint Serre-Swan theorem; introduces Cartan calculus for constraint forms and multivector fields; shows compatibility with reduction.
result Reduction procedure for Lie (bi-)algebroids and Dirac manifolds.

The study counts ideal points in 2-bridge knot complements using knot diagrams.

problem Counting ideal points in 2-bridge knot complements.
method Using knot diagrams, the structure of Serre trees for essential surfaces is determined, leading to a formula for ideal points.
result A formula for the number of ideal points associated with each incompressible surface in 2-bridge knot complements.

This paper addresses questions of quasi-isometric rigidity and classification for fundamental groups of finite graphs of groups, under the assumption that the Bass-Serre tree of the graph of groups has finite depth. The main example of a finite depth graph of groups is one whose vertex and edge groups are coarse Poinca…

2004-05-13abs ↗pdf ↗

Explicitly found generators of cohomology for SL_n(Z) using sharbly cycles and cosharbly cocycles.

problem Finding explicit generators for the cohomology of SL_n(Z).
method Using sharbly cycles and cosharbly cocycles, and applying Borel-Serre duality.
result Explicitly found generators of H_t(SL_n(Z),St) in terms of sharbly cycles and cosharbly cocycles.

Let Γn(p)Γ_n(p) be the level-pp principal congruence subgroup of SLn(Z)\text{SL}_n(\mathbb{Z}). Borel-Serre proved that the cohomology of Γn(p)Γ_n(p) vanishes above degree (n2)\binom{n}{2}. We study the cohomology in this top degree (n2)\binom{n}{2}. Let Tn(Q)\mathcal{T}_n(\mathbb{Q}) denote the Tits building of $\text{SL}_n(\mathbb{Q…

2019-09-05abs ↗pdf ↗

The paper certifies projective rigidity for once-punctured torus bundles using twisted Alexander polynomials.

problem Certifying infinitesimal projective rigidity for hyperbolic once-punctured torus bundles.
method Using twisted Alexander polynomials of representations associated with the holonomy.
result The induced action on the tangent space of the character variety matches the group theoretic action.

For a transversal pair of closed Lagrangian submanifolds L, L' of a symplectic manifold M so that π1(L)=π1(L)=0=c1π2(M)=ωπ2(M)π_{1}(L)=π_{1}(L')=0=c_{1}|_{π_{2}(M)}=ω|_{π_{2}(M)} and a generic almost complex structure J we construct an invariant with a high homotopical content which consists in the pages of order 2\geq 2 of a spectral sequence…

2004-01-09abs ↗pdf ↗

The paper studies the space of Gauss maps of complete minimal surfaces and their homotopy types.

problem Understanding the space of Gauss maps of complete minimal surfaces and their homotopy types.
method Proves the Gauss map assignment is a Serre fibration and determines the homotopy type of the space of meromorphic functions.
result The space of meromorphic functions on MM that are the Gauss map of a complete full conformal minimal immersion has the same homotopy type as the space of all continuous maps from MM to the 2-sphere.

Let X be a locally symmetric space associated to a reductive algebraic group G defined over Q. L-modules are a combinatorial analogue of constructible sheaves on the reductive Borel-Serre compactification of X; they were introduced in [math.RT/0112251]. That paper also introduced the micro-support of an L-module, a com…

2004-12-20abs ↗pdf ↗

Study on cohomology of special linear groups over Euclidean number rings.

problem Understanding cohomology of principal congruence subgroups of special linear groups.
method Analyzing cohomology groups and using properties of Tits buildings.
result Natural map between cohomology and homology is surjective and an isomorphism under certain conditions.