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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.

169,341 papers · 148 categories

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36912 · Jun 202019922001200920182026
48 results for Waldhausen's A-theory

Bökstedt and Madsen defined an infinite loop map from the embedded dd-dimensional cobordism category of Galatius, Madsen, Tillmann and Weiss to the algebraic KK-theory of BO(d)BO(d) in the sense of Waldhausen. The purpose of this paper is to establish two results in relation to this map. The first result is that it exte…

2011-10-14abs ↗pdf ↗

This note is an exposition of Waldhausen's proof of Waldhausen's Theorem: the three-sphere has a single Heegaard splitting, up to isotopy, in every genus. As a necessary step we also give a sketch of the Reidemeister-Singer Theorem.

2009-04-01abs ↗pdf ↗

We define the class of Haken nn--manifolds as a generalisation of Haken 3--manifolds. We prove that the interior of the universal covering of a Haken nn--manifold is $\RR^n$, which generalises a result of Waldhausen. The techniques used allow us to provide a new proof of Waldhausen's universal cover theorem for Haken…

2011-08-02abs ↗pdf ↗

We prove that the Waldhausen Nil-group associated to a virtually cyclic groups that surjects onto the infinite dihedral group vanishes if and only if the corresponding Farrell Nil-group associated to the canonical index two subgroup is trivial. The proof uses the transfer map to establish one direction, and uses contro…

2006-09-25abs ↗pdf ↗

This paper examines the category C^k_{d,n} whose morphisms are d-dimensional smooth manifolds that are properly embedded in the product of a k-dimensional cube with an (d+n-k)-dimensional Euclidean space. There are k directions to compose k-dimensional cubes, so C^k_{d,n} is a (strict) k-tuple category. The geometric r…

2011-02-21abs ↗pdf ↗

The Waldhausen construction of Mayer-Vietoris splittings of chain complexes over an injective generalized free product of group rings is extended to a combinatorial construction of Seifert-van Kampen splittings of CW complexes with fundamental group an injective generalized free product.

2003-08-12abs ↗pdf ↗

Using basic properties of one-sided Heegaard splittings, a direct proof that geometrically compressible one-sided splittings of RP^3 are stabilised is given. The argument is modelled on that used by Waldhausen to show that two-sided splittings of S^3 are standard.

2005-09-01abs ↗pdf ↗

A graph multilink is a link with multiplicities in a homology 3-sphere whose exterior is a graph manifold. In this Note, we compute the Novikov homology of graph multilinks. As a corollary, we give a majoration for the number of Novikov modules on a given graph link.

2004-06-09abs ↗pdf ↗

We describe a new approach to the canonical decompositions of 3-manifolds along tori and annuli due to Jaco-Shalen and Johannson (with ideas from Waldhausen) - the so-called JSJ-decomposition theorem. This approach gives an accessible proof of the decomposition theorem; in particular it does not use the annulus-torus t…

1997-07-30abs ↗pdf ↗

New proof of index theorem for topological manifold bundles.

problem Index theorem for fiber bundles of compact topological manifolds.
method Use of a convenient framework for bivariant theories and recent results on the homotopy type of the topological cobordism category.
result Refinement of the assembly map for an extended A-theory characteristic.

We prove that cubulated hyperbolic groups are virtually special. The proof relies on results of Haglund and Wise which also imply that they are linear groups, and quasi-convex subgroups are separable. A consequence is that closed hyperbolic 3-manifolds have finite-sheeted Haken covers, which resolves the virtual Haken …

2012-04-12abs ↗pdf ↗

The two-category with three-manifolds as objects, h-cobordisms as morphisms, and diffeomorphisms of these as two-morphisms, is extremely rich; from the point of view of classical physics it defines a nontrivial topological model for general relativity. A rather striking amount of work on pseudoisotopy theory [Hatcher, …

2004-07-07abs ↗pdf ↗

A famous example of Casson and Gordon shows that a Haken 3-manifold can have an infinite family of irreducible Heegaard splittings with different genera. In this paper, we prove that a closed non-Haken 3-manifold has only finitely many irreducible Heegaard splittings, up to isotopy. This is much stronger than the Waldh…

2004-08-15abs ↗pdf ↗

We find a geometric invariant of isotopy classes of strongly irreducible Heegaard splittings of toroidal 3-manifolds. Combining this invariant with a theorem of R Weidmann, proved here in the appendix, we show that a closed, totally orientable Seifert fibered space M has infinitely many isotopy classes of Heegaard spli…

2005-04-29abs ↗pdf ↗

A Heegaard splitting of a closed, orientable three-manifold satisfies the disjoint curve property if the splitting surface contains an essential simple closed curve and each handlebody contains an essential disk disjoint from this curve [Thompson, 1999]. A splitting is full if it does not have the disjoint curve proper…

2004-01-28abs ↗pdf ↗

We investigate the orderability properties of fundamental groups of 3-dimensional manifolds. Many 3-manifold groups support left-invariant orderings, including all compact P^2-irreducible manifolds with positive first Betti number. For seven of the eight geometries (excluding hyperbolic) we are able to characterize whi…

2002-11-06abs ↗pdf ↗

For ΓΓ a relatively hyperbolic group, we construct a model for the universal space among ΓΓ-spaces with isotropy on the family VC of virtually cyclic subgroups of ΓΓ. We provide a recipe for identifying the maximal infinite virtually cyclic subgroups of Coxeter groups which are lattices in $O^+(n,1)= \iso(\mathbb H^…

2006-06-19abs ↗pdf ↗

Complete invariant for surfaces in 3-sphere derived from diagrams of fundamental groups.

problem Constructing a complete invariant for closed surfaces in the three-sphere.
method Diagram of fundamental groups, generalization of Kneser conjecture, extensions of Waldhausen's theorem.
result Proves the diagram of fundamental groups is a complete invariant for closed surfaces in the three-sphere.

Developed a theory of local convexity for second order differential equations on Lie algebroids.

problem Analyzing convexity in differential equations on Lie algebroids.
method Theory development for local convexity of SODEs on Lie algebroids.
result Extensive discussion of homogeneous quadratic SODEs on Lie algebroids.

The study provides a structure theorem for a new class of noncompact 3-manifolds.

problem Understanding a new class of noncompact 3-manifolds.
method Proved a structure theorem for irreducible open graph manifolds.
result A canonical 'reduced' decomposition of irreducible open graph manifolds along embedded, incompressible 2-tori.

We introduce a theory of stochastic integration with respect to a family of semimartingales depending on a continuous parameter, as a mathematical background to the theory of bond markets. We apply our results to the problem of super-replication and utility maximization from terminal wealth in a bond market. Finally, w…

2006-02-23abs ↗pdf ↗

The Farrell-Jones Conjecture holds for groups acting acylindrically on trees.

problem Verifying the Farrell-Jones Conjecture for groups acting on trees.
method Analyzing acylindrical actions on simplicial trees and using the Farrell-Jones Conjecture.
result The Farrell-Jones Conjecture holds for groups acting acylindrically on trees.

This paper defines a theory of cobordism for virtual knots and studies this theory for standard and rotational virtual knots and links. Non-trivial examples of virtual slice knots are given. Determinations of the four-ball genus of positive virtual knots are given using the results of a companion paper by the author an…

2014-09-01abs ↗pdf ↗

The paper develops a theory of CC^\infty-superrings and their superschemes.

problem Developing a theory for CC^\infty-superrings and superschemes.
method Proving an equivalence between categories of fair affine CC^\infty-superschemes and fair CC^\infty-superrings.
result A key equivalence between fair affine CC^\infty-superschemes and fair CC^\infty-superrings.

The weak regular coherence is a coarse property of a finitely generated group ΓΓ. It was introduced by G. Carlsson and this author to play the role of a weakening of Waldhausen's regular coherence as part of computation of the integral K-theoretic assembly map. A new class of metric spaces (sFDC) was introduced recent…

2013-07-19abs ↗pdf ↗

We study Farrell Nil-groups associated to a finite order automorphism of a ring RR. We show that any such Farrell Nil-group is either trivial, or infinitely generated (as an abelian group). Building on this first result, we then show that any finite group that occurs in such a Farrell Nil-group occurs with infinite mu…

2014-03-27abs ↗pdf ↗

A theory of feature geometry using spectral analysis of weight matrices.

problem Current methods decompose neural network activations into sparse linear features, losing geometric structure.
method Develops a theory by analyzing the spectra of weight-derived matrices, introducing the frame operator.
result Features collapse onto single eigenspaces, organizing into tight frames, and admit discrete classification.

Paper develops a theory for Patterson-Sullivan measures in higher rank symmetric spaces.

problem Establishing existence and uniqueness of Patterson-Sullivan measures in higher rank symmetric spaces.
method Develops theory for vector-valued horofunction boundaries and shadows.
result Proves existence and uniqueness of Patterson-Sullivan measures for transverse groups.

We develop a theory of `non-uniformly local' tent spaces on metric measure spaces. As our main result, we give a remarkably simple proof of the atomic decomposition.

2013-09-23abs ↗pdf ↗

New invariant identifies complex line arrangements with same combinatorics but different embeddings.

problem Identify Zariski pairs with same combinatorics but different line arrangements.
method Study inclusion map of boundary manifold to exterior, analyze homology classes, compute invariant using Sage.
result New invariant distinguishes line arrangements with same combinatorics but different embeddings.

A theory of deep learning is emerging, focusing on training dynamics and statistics.

problem Develop a scientific theory to understand deep learning.
method Synthesize research into five areas: idealized settings, tractable limits, mathematical laws, hyperparameters, and universal behaviors.
result The emerging theory is a mechanics of the learning process, named learning mechanics.