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arXiv research

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.

168,657 papers · 148 categories

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119239358477 · Jun 202019922001200920172026
48 results for fixed point theorems

The study proves fixed-point theorems for groups acting on CAT(0) spaces.

problem Finding fixed points for groups acting on CAT(0) spaces.
method Bootstrapping technique with Helly-type theorems to prove intersections of fixed-point sets.
result Lower bounds on the smallest dimension for groups to act on CAT(0) spaces without global fixed points.

Paper extends Brouwer Fixed Point Theorem with amiable and almost amiable fixed sets.

problem Extending the Brouwer Fixed Point Theorem to approximate fixed sets.
method Introducing shape boundary regions in CW spaces as amiable and almost amiable fixed subsets of dpc maps.
result Variation of Jordan Curve Theorem and Fixed Cell Complex Theorem.

A homological selection theorem for C-spaces, as well as, a finite-dimensional homological selection theorem is established. We apply the finite-dimensional homological selection theorem to obtain fixed-point theorems for usco homologically UV^n set-valued maps.

2016-05-11abs ↗pdf ↗

Banach's fixed point theorem for contraction maps has been widely used to analyze the convergence of iterative methods in non-convex problems. It is a common experience, however, that iterative maps fail to be globally contracting under the natural metric in their domain, making the applicability of Banach's theorem li…

2017-02-23abs ↗pdf ↗

Using an elementary argument, we prove new fixed point theorems for classical elliptic complexes. We obtain new results for conformal relations and coisotropic intersections. We obtain theorems for the average intersections of families of special lagrangian and lagrangian varieties in certain homogeneous spaces.

2006-06-22abs ↗pdf ↗

Paper proves new method for constructing initial data in general relativity.

problem Proving the existence of solutions for initial data in general relativity.
method Using the Banach fixed point theorem to prove existence, with guarantees of uniqueness and explicit construction.
result Guaranteed uniqueness and explicit construction of solutions to the conformal method equations.

The main result in this paper is a fixed point formula for equivariant indices of elliptic differential operators, for proper actions by connected semisimple Lie groups on possibly noncompact manifolds, with compact quotients. For compact groups and manifolds, this reduces to the Atiyah-Segal-Singer fixed point formula…

2017-01-30abs ↗pdf ↗

A fixed point theorem is proved for inverse transducers, leading to an automata-theoretic proof of the fixed point subgroup of an endomorphism of a finitely generated virtually free group being finitely generated. If the endomorphism is uniformly continuous for the hyperbolic metric, it is proved that the set of regula…

2012-03-07abs ↗pdf ↗

We prove a global fixed point theorem for the centralizer of a homeomorphism of the two dimensional disk DD that has attractor-repeller dynamics on the boundary with at least two attractors and two repellers. As one application, we show that there is a finite index subgroup of the centralizer of a pseudo-Anosov homeom…

2008-01-04abs ↗pdf ↗

M Handel has proved in [Topology 38 (1999) 235--264] a fixed point theorem for an orientation preserving homeomorphism of the open unit disk, that may be extended to the closed disk and that satisfies a linking property of orbits. We give here a new proof of Handel's fixed point theorem, based on Brouwer theory and som…

2009-03-02abs ↗pdf ↗

Gromov showed that for fixed, arbitrarily large C, any uniformly C-Lipschitz affine action of a random group in his graph model on a Hilbert space has a fixed point. We announce a theorem stating that more general affine actions of the same random group on a Hilbert space have a fixed point. We discuss some aspects of …

2017-05-07abs ↗pdf ↗

We generalise the Atiyah-Segal-Singer fixed point theorem to noncompact manifolds. Using KKKK-theory, we extend the equivariant index to the noncompact setting, and obtain a fixed point formula for it. The fixed point formula is the explicit cohomological expression from Atiyah-Segal-Singer's result. In the noncompact …

2015-12-24abs ↗pdf ↗

Fixed points found in cluster modular groups under specific conditions.

problem Proving fixed points in cluster modular groups.
method Generalizing Kerckhoff's Nielsen realization theorem for cluster modular groups, using convexity of log-cluster variables.
result Finite subgroups of cluster modular groups have fixed points in cluster manifolds under certain conditions.

Paper finds efficient algorithms for computing fixed points in financial networks.

problem Computing fixed points in complex financial networks with potential defaults.
method Tarski's theorem and polynomial-time algorithms for minimal and maximal fixed points.
result Efficient algorithms for computing minimal and maximal fixed points in financial networks.

In this paper we give a natural condition for when a volumorphism on a Riemannian manifold (M,g)(M,g) is actually an isometry with respect to some other, optimal, Riemannian metric hh. We consider the natural action of volumorphisms on the space $\M_μ^s$ of all Riemannian metrics of Sobolev class HsH^s, s>n/2s>n/2, with a f…

2012-06-02abs ↗pdf ↗

In this paper we show that the Seiberg--Witten invariant is zero for all smooth 4--manifolds with b+>1b_+{>}1 which admit circle actions that have at least one fixed point. Furthermore, we show that all symplectic 4--manifolds which admit circle actions with fixed points are rational or ruled, and thus admit a symplectic…

2002-01-07abs ↗pdf ↗

The paper proves a theorem about fixed points and relates it to the Nielsen realisation problem.

problem The Nielsen realisation problem for aspherical manifolds.
method Proof of a theorem about fixed points and its relation to the Nielsen realisation problem.
result The coincidence of genuine and homotopy fixed points for isometric group actions on nonpositively curved manifolds.

We present proofs of basic results, including those developed by Harold Bell, for the plane fixed point problem: does every map of a non-separating plane continuum have a fixed point? Some of these results had been announced much earlier by Bell but without accessible proofs. We define the concept of the variation of a…

2010-04-01abs ↗pdf ↗

The purpose of this expository paper is to present new directions in the classical Nielsen-Reidemeister fixed point theory. We describe twisted Burnside-Frobenius theorem, groups with RR_\infty \emph{property} and a connection between Nielsen fixed point theory and symplectic Floer homology.

2007-12-17abs ↗pdf ↗

The Grove-Searle theorem on 2d manifolds with 8 or less symmetry groups has positive Euler characteristic.

problem Proving positive Euler characteristic for 2d manifolds with specific symmetry groups.
method Direct proof and analysis of fixed point components N with geodesic properties.
result Fixed point components N have amazing geodesic properties and can be S^2, RP^2, CP^d, HP^d, etc.

Recent proofs of classical theorems in polynomial algebra and functional analysis are discussed, which use tools from the topology of real manifolds. Simpler proofs were discovered in the new century, of the Hilbert Nullstellensatz, and the Gelfand-Mazur Theorem. We give a related proof that an irreducible real polynom…

2015-02-01abs ↗pdf ↗

Global fixed points in low-dimensional surface group space correspond to trivial representations.

problem Understanding global fixed points in surface group deformation spaces.
method Direct analysis of the deformation space, focusing on the trivial representation.
result Global fixed points in low-dimensional surface group deformation spaces correspond to the trivial representation of the pure mapping class group.

Study of loop braid groups for 3D manifolds, linking algebra and dynamics.

problem Lack of a 3D framework for braid group theory in topological dynamics.
method Introduce loop braid groups and associate Burau matrix representations with generalized Lefschetz number.
result Established a connection between loop braid groups and topological dynamical properties, providing estimates for periodic points.

The proof of Brouwer's fixed-point theorem based on Sperner's lemma is often presented as an elementary combinatorial alternative to advanced proofs based on algebraic topology. The goal of this note is to show that: (i) the combinatorial proof of Sperner's Lemma can be considered as a cochain-level version, written in…

2009-06-29abs ↗pdf ↗

In this paper, we first prove a local family version of the Atiyah-Bott-Segal-Singer Lefschetz fixed point formula, then we extend the famous Witten's rigidity Theorems to the family case. Several family vanishing theorems for elliptic genera are also proved.

1999-10-08abs ↗pdf ↗

A recent anomaly computation of Horava and Witten is proved and generalized in the form of two index theorems in odd dimensions. Theorem A is a fixed point formula for orientation-reversing involutions. Theorem B is an index theorem for manifolds with boundary using local boundary conditions. Both hold for families of …

1996-01-15abs ↗pdf ↗

Study solves optimal portfolio selection using HJB equation.

problem Optimal portfolio selection problem.
method Maximal monotone operator method, Banach fixed-point theorem, Fourier transform, monotone operators technique.
result Existence and uniqueness of solution to HJB equation.

Paper generalizes Hardy-Rogers maps for market equilibrium analysis in duopoly markets.

problem Existence and uniqueness of market equilibrium in duopoly markets with non-differentiable, nonlinear response functions.
method Coupled fixed points approach for generalized Hardy-Rogers maps.
result Enriched understanding of market equilibrium in duopoly markets with non-differentiable response functions.