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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.

168,695 papers · 148 categories

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18365472 · Jun 202019922001200920172026
48 results for Fredholm modules

We construct a Fredholm module on self-similar sets such as the Cantor dust, the Sierpinski carpet and the Menger sponge. Our construction is a higher dimensional analogue of Connes' combinatorial construction of the Fredholm module on the Cantor set. We also calculate the Dixmier trace of two operators induced by the …

2019-12-12abs ↗pdf ↗

Paper proves equality of K-homology classes for compact complex spaces.

problem Analyzing canonical K-homology classes on compact complex spaces.
method Functional analytic techniques, homotopy between Fredholm modules.
result Equality of K-homology classes [ðF,m,abs]=π[ðE,m][\overlineð_{F,m,\mathrm{abs}}]=π_*[\overlineð_{E,m}].

Let {T1,,Tn}\{T_1, \ldots, T_n\} be a set of nn commuting bounded linear operators on a Hilbert space H\mathcal{H}. Then the nn-tuple (T1,,Tn)(T_1, \ldots, T_n) turns H\mathcal{H} into a module over C[z1,,zn]\mathbb{C}[z_1, \ldots, z_n] in the following sense: \[\mathbb{C}[z_1, \ldots, z_n] \times \mathcal{H} \raro \clh, \quad \quad …

2013-08-28abs ↗pdf ↗

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.

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.

We construct analytically the signature operator for a new family of topological manifolds. This family contains the quasi-conformal manifolds and the topological manifolds modeled on germs of homeomorphisms of R^n possessing a derivative which is in L^p, with p > n(n+1)/2. We obtain an unbounded Fredholm module which …

1999-05-01abs ↗pdf ↗

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.

For a pseudodifferential operator SS of order 0 acting on sections of a vector bundle BB on a compact manifold MM without boundary, we associate a differential form of order dimension of MM acting on C(M)×C(M)C^\infty(M)\times C^\infty(M). This differential form Ωn,SΩ_{n,S} is given in terms of the Wodzicki 1-density $\wres…

2002-11-22abs ↗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 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.

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.

On a 6-dimensional, conformal, oriented, compact manifold MM without boundary, we compute a whole family of differential forms Ω6(f,h)Ω_6(f,h) of order 6, with f,hC(M).f,h \in C^\infty(M). Each of these forms will be symmetric on f,f, and h,h, conformally invariant, and such that Mf0Ω6(f1,f2)\int_M f_0 Ω_6(f_1,f_2) defines a Hochschild 2-…

2002-11-15abs ↗pdf ↗

Let XX be a compact manifold with boundary. Suppose that the boundary is fibred, $φ:\pa X\longrightarrow Y,$ and let $x\in\CI(X)$ be a boundary defining function. This data fixes the space of `fibred cusp' vector fields, consisting of those vector fields VV on XX satisfying Vx=O(x2)Vx=O(x^2) and which are tangent to the f…

1998-12-18abs ↗pdf ↗

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.

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 ↗

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 ↗

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.

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.

Study the exponential map on surfaces using fluid dynamics.

problem Exponential map of volume-preserving diffeomorphisms on closed surfaces.
method Fluid dynamical proof of Ebin--Misiołek--Preston theorem and extension of Shnirelman's rigidity result.
result Exponential map is a nonlinear Fredholm mapping of index zero and Fredholm quasiregular.

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 ↗

The main topic is the development of a Fredholm theory in a new class of spaces called M-polyfolds. In the subsequent Volume II the theory will be generalized to an even larger class of spaces called polyfolds, which can also incorporate local symmetries. The whole package provides a functional analytic framework to de…

2014-07-11abs ↗pdf ↗

This is the revised version of the second paper in a series introducing a generalized Fredholm theory in a new class of smooth spaces called polyfolds. The theory will be illustrated in upcoming papers by applications to Floer Theory, Gromov-Witten Theory and Symplectic Field Theory. Some proofs have been improved and …

2007-05-09abs ↗pdf ↗

We analyse the problem of assigning sign choices to O-planes in orientifolds of type II string theory. We show that there exists a sequence of invariant pp-gerbes with p1p\geq-1, which give rise to sign choices and are related by coboundary maps. We prove that the sign choice homomorphisms stabilise with the dimension…

2019-05-15abs ↗pdf ↗

We study both the continuous model and the discrete model of the integer quantum Hall effect on the hyperbolic plane in the presence of disorder, extending the results of an earlier paper [CHMM]. Here we model impurities, that is we consider the effect of a random or almost periodic potential as opposed to just periodi…

1998-04-27abs ↗pdf ↗

The square root of Fredholm determinants causes numerical instabilities in option pricing models.

problem Numerical instabilities in Fourier-based option pricing for the Volterra Stein-Stein model.
method Characterization of determinant crossing behavior, derivation of transform to handle crossings, efficient algorithms.
result Significant improvement in accuracy and reduction in computational cost for Fourier-based pricing.

Noncommutative Kähler structures were recently introduced as an algebraic framework for studying noncommutative complex geometry on quantum homogeneous spaces. In this paper, we introduce the notion of a \emph{compact quantum homogeneous Kähler space} which gives a natural set of compatibility conditions between covari…

2019-10-30abs ↗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.