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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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96193289385 · May 202619922001200920172026
48 results for Fredholm conditions

The paper calculates indices for families of Fredholm operators and their extensions.

problem Calculating indices for families of Fredholm operators and their extensions.
method Passing from a Fredholm operator to its graph, deforming the horizontal subspace.
result Index formulas for families of Fredholm realizations and self-adjoint extensions.

Study perturbs APS boundary conditions for Lorentzian Dirac operators.

problem Maintaining Fredholmness of Dirac operators under perturbations of APS boundary conditions.
method Develop criteria for perturbing compact pairs of projections to remain Fredholm.
result Criteria for perturbing APS boundary conditions without losing Fredholmness.

Study shows Fredholmness of a Lorentzian Dirac operator on spacetimes.

problem Analyzing Fredholmness of a Lorentzian Dirac operator on spacetimes.
method Investigates Fredholmness of a (spatial) Γ-invariant Lorentzian Dirac operator under (anti) Atiyah-Patodi-Singer boundary conditions.
result Demonstrates Fredholmness of the operator in the von Neumann sense.

Derives Fredholm criteria for isotypical components from a Simonenko principle.

problem Finding Fredholm conditions for isotypical components of invariant pseudodifferential operators.
method General Simonenko's local principle and equivariant local principle for restriction to isotypical components.
result Full proof of equivariant local principle and extension of results.

The spectral flow theorem is applied to operators on finite intervals.

problem Operators on finite intervals without boundary conditions are not Fredholm.
method Interpolation theory is used to define boundary conditions making the operators Fredholm. The spectral flow theorem is applied to find the Fredholm index.
result The Fredholm index is given by the spectral flow of the operator path.

Fredholm conditions for invariant operators on compact manifolds.

problem Characterizing operators with Fredholm maps induced by their action on manifolds.
method Defining transversally αα-elliptic operators and proving Fredholmness based on their principal symbols and group actions.
result Operators are Fredholm if and only if they are transversally αα-elliptic.

We prove some Fredholm conditions for many algebras of differential operators on particular classes of open manifolds, which include asymptotically Euclidean or asymptotically hyperbolic manifolds. Our typical result is that an operator PP is Fredholm if, and only if, it is elliptic and some limit operators $(P_α)_{α\…

2018-08-04abs ↗pdf ↗

Researchers prove Fredholm property for Dirac operator on specific spacetimes.

problem Proving Fredholm property for Dirac operator on asymptotically static spacetimes.
method Combining time-dependent scattering theory and Egorov's theorem for pseudo-differential hyperbolic systems.
result The Dirac operator is Fredholm under Atiyah-Patodi-Singer boundary conditions.

We show that elliptic complexes of (pseudo)differential operators on smooth compact manifolds with boundary can always be complemented to a Fredholm problem by boundary conditions involving global pseudodifferential projections on the boundary (similarly as the spectral boundary conditions of Atiyah, Patodi and Singer …

2015-10-08abs ↗pdf ↗

Characterizes Fredholm conditions for group-invariant pseudodifferential operators.

problem Understanding Fredholm conditions for operators on quotient spaces.
method Study of symbol CC^*-algebra and topology of primitive ideal spectrum.
result Explicit characterization of Fredholm operators in terms of principal symbol and group action.

The paper studies elliptic operators on manifolds with boundary.

problem Characterizing boundary conditions for elliptic operators on manifolds.
method Using Calderón projectors and mixed order Sobolev spaces, the paper describes the space of boundary values and characterizes Fredholm and regular realisations.
result Characterization of boundary conditions for elliptic operators leading to Fredholm and regular realisations.

Novel approach to Nash equilibrium in mean-field stochastic games with operator resolvents.

problem Finding Nash equilibrium in mean-field stochastic games with mean-field interaction.
method Proposed a novel approach to derive Nash equilibrium semi-explicitly using operator resolvents and stochastic Fredholm equations.
result Equilibrium of the NN-player game converges to mean-field equilibrium, and ε\varepsilon-Nash equilibrium derived as a by-product.

Extends Atiyah-Singer Dirac operator study to non-compact spacetimes.

problem Analyzing Dirac operator on non-compact spacetimes with non-compact Cauchy hypersurface.
method Building on previous works, extends Fredholm result to non-compact Lorentzian spaces, using von Neumann algebras and Galois coverings.
result Γ-Fredholmness of the Dirac operator under APS boundary conditions.

Classifies non-linear Fredholm maps linking to stable homotopy groups of spheres.

problem Classifying non-linear proper Fredholm maps between Hilbert spaces.
method Using stable homotopy groups of spheres to classify maps up to proper homotopy.
result Determines the non-trivial kernel of the map from stable homotopy groups to non-linear proper Fredholm maps.

New Fredholm criteria for pseudodifferential operators on manifolds.

problem Characterizing the Fredholm property of GG-pseudodifferential operators.
method General Simonenko principle applied to GG-pseudodifferential operators on Sobolev spaces of sections of vector bundles.
result Derivation of novel Fredholm criteria and further characterization for finite groups.

Study of elliptic boundary value problems on non-compact manifolds.

problem Analyzing elliptic differential operators on manifolds with non-compact boundaries.
method Regularity theory and trace theorems for sections in the maximal domain under various assumptions.
result Systematic study of local and nonlocal boundary conditions, including the Atiyah-Patodi-Singer condition.

The aim of this paper is to present the construction, out of the Kohn-Rossi complex, of a new hypoelliptic operator QLQ_{L} on almost CR manifolds equipped with a real structure. The operator acts on all (p,q)-forms, but when restricted to (p,0)-forms and (p,n)-forms it is a sum of squares up to sign factor and lower o…

2008-08-27abs ↗pdf ↗

On any given compact (n+1)-manifold M with non-empty boundary, it is proved that the moduli space of Einstein metrics on M is a smooth, infinite dimensional Banach manifold under a mild condition on the fundamental group. Thus, the Einstein moduli space is unobstructed. The Dirichlet and Neumann boundary maps to data o…

2006-12-21abs ↗pdf ↗

This article provides a version of scale calculus geared towards a notion of (nonlinear) Fredholm maps between certain types of Frechet spaces, retaining as many as possible of the properties Fredholm maps between Banach spaces enjoy, and the existence of a constant rank theorem for such maps. It does so by extending t…

2016-02-23abs ↗pdf ↗

The abstract extends deformation and tangent groupoid constructions to infinite-dimensional manifolds.

problem Deformation and tangent groupoid constructions for infinite-dimensional manifolds.
method Extending finite-dimensional constructions to Banach and Fredholm manifolds.
result Induced generalized filtrations of tangent bundles and groupoids.

We investigate Seiberg-Witten theory in the presence of real structures. Certain conditions are obtained so that integer valued real Seiberg-Witten invariants can be defined. In general we study properties of the real Seiberg-Witten projection map from the point of view of Fredholm map degrees.

2009-05-03abs ↗pdf ↗

We show that the existence of a Fredholm element of the zero calculus of pseudodifferential operators on a compact manifold with boundary with a given elliptic symbol is determined, up to stability, by the vanishing of the Atiyah-Bott obstruction. It follows that, up to small deformations and stability, the same symbol…

2006-07-06abs ↗pdf ↗

We describe a (nonlinear) Fredholm theory for a new class of ambient spaces, as well as for a certain type of categories. The theory is illustrated by an application to the category of stable maps.

2014-12-13abs ↗pdf ↗

We study transversality for Lipschitz-Fredholm maps in the context of bounded Fréchet manifolds. We show that the set of all Lipschitz-Fredholm maps of a fixed index between Fréchet spaces has the transverse stability property. We give a straightforward extension of the Smale transversality theorem by using the general…

2015-08-21abs ↗pdf ↗

Injective and surjective neural operators for function spaces.

problem Tackles injective and surjective neural operators in function spaces.
method Combines prior work in ReLU and operator learning, uses Fredholm theory and Leray-Schauder degree theory.
result Injective and surjective neural operators are universal approximators and maintain their properties in finite-rank implementations.

Optimal trading strategy under market resistance and concave price impact model.

problem Optimal trading in a market with endogenous resistance and concave price impact.
method Modeling market resistance, deriving a stochastic Fredholm equation, proving existence and uniqueness, proposing an iterative scheme.
result Existence and uniqueness of optimal control under certain conditions, exponential convergence of iterative scheme.

The paper solves obstructions to the Fredholm perturbation property for manifolds with corners.

problem Obstructions to the Fredholm perturbation property for compact connected manifolds with corners.
method Introduces a topological space whose singular cohomology is canonically isomorphic to conormal homology and whose K-theory is naturally isomorphic to the K-theory groups of the algebra K_b(X).
result Provides a rational isomorphism between K-theory groups and periodic conormal homology groups, solving obstructions to the Fredholm perturbation property.

We describe two topologies on the space of unbounded Fredholm operators and we explain their K-theoretic relevance. In the process we also prove a very general result concerning the continuity of families of first order, elliptic boundary value problems.

2000-05-09abs ↗pdf ↗

We explain the topology of the space, so called, Fredholm-Lagrangian-Grassmannain and the quantity ``Maslov index'' for paths in this space based on the standard theory of Functional Analysis. Our standing point is to define the Maslov index for arbitrary paths in terms of the fundamental spectral property of the Fredh…

2003-11-27abs ↗pdf ↗

On a compact globally hyperbolic Lorentzian spin manifold with smooth spacelike Cauchy boundary the (hyperbolic) Dirac operator is known to be Fredholm when Atiyah-Patodi-Singer boundary conditions are imposed. In this paper we investigate to what extent these boundary conditions can be replaced by more general ones an…

2017-04-11abs ↗pdf ↗

We consider the mapping properties of generalized Laplace-type operators L=+R{\mathcal L} = \nabla^* \nabla + {\mathcal R} on the class of quasi-asymptotically conical (QAC) spaces, which provide a Riemannian generalization of the QALE manifolds considered by Joyce. Our main result gives conditions under which such opera…

2014-06-13abs ↗pdf ↗