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Related papers: Joint torsion of several commuting operators

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It is known that the set of all solutions of a commutant lifting and other interpolation problems admits a Redheffer linear-fractional parametrization. The method of unitary coupling identifies solutions of the lifting problem with minimal…

Functional Analysis · Mathematics 2010-04-06 Joseph A. Ball , Alexander Kheifets

We generalize the winding number formula for the Fredholm index of a Toeplitz operator to the Witten index. We also show trace formulae involving Toeplitz operators and operator monotone functions.

Functional Analysis · Mathematics 2025-01-28 Masaki Izumi

Let $T = (T_1, \ldots, T_n)$ be a commuting tuple of bounded linear operators on a Hilbert space $\mathcal{H}$. The multiplicity of $T$ is the cardinality of a minimal generating set with respect to $T$. In this paper, we establish an…

Functional Analysis · Mathematics 2023-06-22 Arup Chattopadhyay , Jaydeb Sarkar , Srijan Sarkar

A major open question in the theory of Toeplitz operator on the Bergman space of the unit disk of the complex plane is the complete characterization of the set of all Toeplitz operators that commute with a given operator. In \cite{al}, the…

Functional Analysis · Mathematics 2024-09-24 Aissa Bouhali , Issam Louhichi

We prove that the isomonodromic tau function on a torus with Fuchsian singularities and generic monodromies in $GL(N,\mathbb{C})$ can be written in terms of a Fredholm determinant of Cauchy-Plemelj operators. We further show that the minor…

Mathematical Physics · Physics 2023-03-17 Fabrizio Del Monte , Harini Desiraju , Pavlo Gavrylenko

We employ the pinching theorem, ensuring that some operators A admit any sequence of contractions as an operator diagonal of A, to deduce/improve two recent theorems of Kennedy-Skoufranis and Loreaux-Weiss for conditional expectations onto…

Functional Analysis · Mathematics 2015-05-12 Jean-Christophe Bourin , Eun-Young Lee

This paper consists of four parts. It begins by using the authors's generalized Schauder formula, [50], and the algebraic multiplicity, $\chi$, of Esquinas and L\'opez-G\'omez [18,17,40] to package and sharpening all existing results in…

Analysis of PDEs · Mathematics 2023-04-05 Julián López-Gómez , Juan Carlos Sampedro

In this note known formulas for the product of Toeplitz operators are revisited in the context of their applications to the study of Fredholmness, boundedness of Toeplitz products, and the Berezin-Toeplitz quantization. A few open problems…

Functional Analysis · Mathematics 2023-01-03 Jani A. Virtanen

Using Kakichev's classical concept and extending Yakubovich-Britvina's approach (\textit{Results. Math.} 55(1-2):175-197, 2009) and (\textit{Integral Transforms Spec. Funct.} 21(4):259--276, 2010) for setting up Kontorovich-Lebedev…

Classical Analysis and ODEs · Mathematics 2025-07-22 Trinh Tuan

We study an invariant, the secondary trace, attached to two commuting endomorphisms of a 2-dualizable object in a symmetric monoidal higher category. We establish a secondary trace formula which encodes the natural symmetries of this…

Algebraic Geometry · Mathematics 2013-06-04 David Ben-Zvi , David Nadler

Let T:=[T_1,..., T_n] be an n-tuple of operators on a Hilbert space such that T is a completely non-coisometric row contraction. We establish the existence of a "one-to-one" correspondence between the joint invariant subspaces under…

Functional Analysis · Mathematics 2007-05-23 Gelu Popescu

Frame multipliers are an abstract version of Toeplitz operators in frame theory and consist of a composition of a multiplication operator with the analysis and synthesis operators. Whereas the boundedness properties of frame multipliers on…

Functional Analysis · Mathematics 2025-06-24 Peter Balazs , Karlheinz Gröchenig

We study the $p$-\emph{torsion function} and the corresponding $p$-\emph{torsional rigidity} associated with $p$-Laplacians and, more generally, $p$-Schr\"odinger operators, for $1<p<\infty$, on possibly infinite combinatorial graphs. We…

Spectral Theory · Mathematics 2024-10-14 Patrizio Bifulco , Delio Mugnolo

We introduce and study twist vertex operators for a (lower-bounded generalized) twisted modules for a grading-restricted vertex (super)algebra. We prove duality, weak associativity, a Jacobi identity, a generalized commutator formula,…

Quantum Algebra · Mathematics 2019-08-28 Yi-Zhi Huang

Fredholm integral operators that commute with the Hamiltonians of certain quantum mechanical problems with quartic potentials are introduced. The operators are expressed in terms of an Airy function, and their eigenvalues fall off…

High Energy Physics - Theory · Physics 2026-03-13 Ori J. Ganor

By the introduction of a generalized Evans function defined by an appropriate 2-modified Fredholm determinant, we give a simple proof of convergence in location and multiplicity of Hill's method for numerical approximation of spectra of…

Numerical Analysis · Mathematics 2010-09-21 Mathew A. Johnson , Kevin Zumbrun

We relate dual-band general Toeplitz operators to block truncated Toeplitz operators and, via equivalence after extension, with Toeplitz operators with $4 \times 4$ matrix symbols. We discuss their norm, their kernel, Fredhomlness,…

Functional Analysis · Mathematics 2021-06-04 M. Cristina Câmara , Ryan O'Loughlin , Jonathan R. Partington

Our main aim is to investigate the approximation properties for the summation integral type operators in a statistical sense. In this regard, we prove the statistical convergence theorem using well known Korovkin theorem and the degree of…

Functional Analysis · Mathematics 2019-12-24 Rishikesh Yadav , Ramakanta Meher , Vishnu Narayan Mishra

We establish an index theorem for Toeplitz operators on odd dimensional spin manifolds with boundary. It may be thought of as an odd dimensional analogue of the Atiyah-Patodi-Singer index theorem for Dirac operators on manifolds with…

Differential Geometry · Mathematics 2007-05-23 Xianzhe Dai , Weiping Zhang

We extend the relative index theorem on non-compact manifolds to encompass a wide variety of hypoelliptic differential operators of arbitrary order, demonstrating that the change in index when changing a differential operator locally can be…

K-Theory and Homology · Mathematics 2025-11-11 Magnus Fries