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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.

168,657 papers · 148 categories

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24477194 · Jun 202019922001200920172026
48 results for Hilbert modules

A commuting nn-tuple (T1,,Tn)(T_1, \ldots, T_n) of bounded linear operators on a Hilbert space $\clh$ associate a Hilbert module H\mathcal{H} 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} \rightarrow \mathcal{H}, \quad \quad (p, h) \mapsto p(T_1, \ldots, T_n)h…

2014-09-27abs ↗pdf ↗

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 ↗

In this paper, we consider the similarity and quasi-affinity problems for Hilbert modules in the Cowen-Douglas class associated with the complex geometric objects, the hermitian anti-holomorphic vector bundles and curvatures. Given a "simple" rank one Cowen-Douglas Hilbert module M\mathcal{M}, we find necessary and su…

2012-12-12abs ↗pdf ↗

In this paper we introduce the curvature of densely defined universal connections on Hilbert CC^{*}-modules relative to a spectral triple (or unbounded Kasparov module), obtaining a well-defined curvature operator. Fixing the spectral triple, we find that modulo junk forms, the curvature only depends on the represente…

2019-11-12abs ↗pdf ↗

In this paper we interpret the integrability of the Dirac structures on some Hilbert C*-modules in terms of an automorphism group. This is the group of orthogonal transformations on the Hilbert C*-module of sections of a Hermitian vector bundle over an smooth manifold M. Some topological properties of the group of inte…

2009-08-03abs ↗pdf ↗

We derive a general obstruction to the existence of Riemannian metrics of positive scalar curvature on closed spin manifolds in terms of hypersurfaces of codimension two. The proof is based on coarse index theory for Dirac operators that are twisted with Hilbert C*-module bundles. Along the way we give a complete and s…

2014-02-17abs ↗pdf ↗

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 ↗

For a CC^*-algebra AA of compact operators and a compact manifold M,M, we prove that the Hodge theory holds for AA-elliptic complexes of pseudodifferential operators acting on smooth sections of finitely generated projective AA-Hilbert bundles over M.M. For these CC^*-algebras, we get also a topological isomorphis…

2015-06-20abs ↗pdf ↗

The conformal module of conjugacy classes of braids implicitly appeared in a paper of Lin and Gorin in connection with their interest in the 13. Hilbert Problem. This invariant is the supremum of conformal modules (in the sense of Ahlfors) of certain annuli related to the conjugacy class. This note states that the conf…

2012-08-07abs ↗pdf ↗

We lift ambit fields as introduced by Barndorff-Nielsen and Schmiegel to a class of Hilbert space-valued volatility modulated Volterra processes. We name this class Hambit fields, and show that they can be expressed as a countable sum of weighted real-valued volatility modulated Volterra processes. Moreover, Hambit fie…

2015-09-28abs ↗pdf ↗

The paper shows robustness of Hilbert space-valued stochastic volatility models to perturbations.

problem Robustness of Hilbert space-valued stochastic volatility models to measurement or approximation errors.
method Quantifying the error induced by volatility perturbations and studying robustness of volatility process with finite dimensional approximations.
result Explicit bounds for the induced error in terms of approximation of the underlying parameter.

New measures on orbit spaces for orthogonal groups identified.

problem Characterizing measures on orbit spaces of orthogonal groups.
method Constructing Hilbert measures on orbit spaces of coregular representations of orthogonal groups.
result Hilbert measures have singularities if and only if the number of copies equals the dimension.

For a closed manifold equipped with a Riemannian metric, a triangulation, a representation of its fundamental group on an Hilbert module of finite type (over of finite von Neumann algebra), and a Hermitian structure on the flat bundle associated to the representation, one defines a numerical invariant, the relative tor…

1997-11-25abs ↗pdf ↗

For a symplectic manifold admitting a metaplectic structure and for a Kuiper map, we construct a complex of differential operators acting on exterior differential forms with values in the dual of the Kostant's symplectic spinor bundle. Defining a Hilbert CC^*-structure on this bundle for a suitable CC^*-algebra, we o…

2017-11-27abs ↗pdf ↗

In the work we discuss two invariants of conjugacy classes of braids. The first invariant is the conformal module which occurred in connection with the interest in the 13th Hilbert Problem. The second is a popular dynamical invariant, the entropy. It occurred in connection with Thurston's theory of surface homeomorphis…

2014-12-19abs ↗pdf ↗

This research explores complex-valued neural networks and their implementation.

problem The challenges of implementing complex-valued neural networks and their potential for non-complex data.
method Detailed theory and implementation of CVNN, including Wirtinger calculus, complex backpropagation, and modules like complex layers and activation functions. Python implementation using cvnn toolbox.
result Demonstrates the potential of CVNN for non-complex data through simulations.

Generalizes Riemann-Hilbert correspondence for curved local systems.

problem Higher Riemann-Hilbert correspondence with scalar curvature.
method Equivalence of dg-categories of curved local systems, graded vector bundles, and representations.
result Equivalence of dg-enhancements of twisted sheaves categories.

We identify branched coverings (continuous open surjections p:Y->X of Hausdorff spaces with uniformly bounded number of pre-images) with Hilbert C*-modules C(Y) over C(X) and with faithful unital positive conditional expectations E:C(Y)->C(X) topologically of index-finite type. The case of non-branched coverings corres…

2010-02-18abs ↗pdf ↗

Paper generalizes kernel mean embedding to von Neumann-algebra-valued measures.

problem Analyzing complex multivariate distributions and quantum mechanics.
method Generalizes kernel mean embedding to von Neumann-algebra-valued measures in reproducing kernel Hilbert modules.
result Injectivity and universality of the generalized KME are confirmed.

We construct the Calderon projection on the space of Cauchy datas for a twisted Dirac operator in the Mischenko--Fomenko pseudodifferential calculus for operators acting on bundles of finitely generated CC^*--Hilbert modules on a compact manifold with boundary. In particular an invertible double is constructed general…

2013-07-08abs ↗pdf ↗

We present a fairly general construction of unbounded representatives for the interior Kasparov product. As a main tool we develop a theory of C^1-connections on operator * modules; we do not require any smoothness assumptions; our sigma-unitality assumptions are minimal. Furthermore, we use work of Kucerovsky and our …

2011-10-07abs ↗pdf ↗

We define a deformation of the triply graded Khovanov-Rozansky homology of a link LL depending on a choice of parameters ycy_c for each component of LL, which satisfies link-splitting properties similar to the Batson-Seed invariant. Keeping the ycy_c as formal variables yields a link homology valued in triply graded …

2017-12-11abs ↗pdf ↗

The study identifies and analyzes different market regimes in equity markets using advanced signal processing techniques.

problem Understanding and quantifying the dynamics of different market regimes in equity markets.
method Data-driven Hilbert--Huang Transform for regime identification, Holo--Hilbert Spectral Analysis for profiling, and Variable-Length Markov Chains for return dynamics modeling.
result Developed markets normalize more effectively as stress subsides, while developing markets retain residual tail dependence and downside persistence.

In this paper we continue the study of spectral properties of Laplacians associated with an arbitrary smooth distribution on a compact manifold, initiated in a previous paper. Under assumption that the singular foliation generated by the distribution is smooth, we prove that the Laplacian associated with the distributi…

2017-10-27abs ↗pdf ↗

In this paper, we investigate representations of At(N)\operatorname{At}(N), the Atiyah algebroids of a holomorphic line bundles NN over a complex manifold YY. In particular, we relate At(N)\operatorname{At}(N)-modules with logarithmic connections through two functors. On the one hand, we use these functors to the define in…

2015-05-18abs ↗pdf ↗

We describe an AA_\infty-quasi-equivalence of dg-categories between the first authors' PA\mathcal{P}_{\mathcal{A}} ---the category of category of prefect A0A^0-modules with flat Z\Z-connection, corresponding to the de Rham dga A\mathcal{A} of a compact manifold MM--- and the dg-category of \emph{infinity-local syst…

2009-08-20abs ↗pdf ↗

The main result of this paper is the following: any `weighted' Riemannian manifold (M,g,μ)(M,g,μ) - i.e. endowed with a generic non-negative Radon measure μμ - is `infinitesimally Hilbertian', which means that its associated Sobolev space W1,2(M,g,μ)W^{1,2}(M,g,μ) is a Hilbert space. We actually prove a stronger result: the abstrac…

2018-09-16abs ↗pdf ↗

Adler had shown in 1979 that the Toda system can be given a coad- joint orbit description. We quantize the Toda system by viewing it as a single orbit of a multiplicative group of lower triangular matrices of determinant one with pos- itive diagonal entries. We get a unitary representation of the group with square inte…

2016-12-09abs ↗pdf ↗

In this paper we state and prove a higher index theorem for an odd-dimensional connected spin riemannian manifold (M,g)(M,g) which is partitioned by an oriented closed hypersurface NN. This index theorem generalizes a theorem due to N. Higson and J. Roe in the context of Hilbert modules. Then we apply this theorem to pro…

2008-12-08abs ↗pdf ↗

Deep learning framework for kernel methods using RKHM and Perron-Frobenius operators.

problem Kernel methods in deep learning with potential overfitting issues.
method Combining RKHM and Perron-Frobenius operator to derive a new Rademacher bound and analyze deep kernel methods.
result Theoretical interpretation of benign overfitting and milder dependency on output dimension.