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To each real continuous function f there is an associated trace function on real symmetric matrices Tr f. The classical Klein lemma states that f is convex if and only if Tr f is convex. In this note we present an algebraic strengthening of…

Operator Algebras · Mathematics 2018-04-27 Igor Klep , Scott A. McCullough , Christopher S. Nelson

The paper establishes the Krein and Koplienko trace formulas for multivariable operator functions on symmetrically normed ideals of bounded operators. Results are proved for self-adjoint and maximal dissipative operators. They cover both…

Functional Analysis · Mathematics 2026-05-18 Arup Chattopadhyay , Saikat Giri , Chandan Pradhan , Alexandr Usachev

We study the convexity properties of the generalized trigonometric functions considered as functions of parameter. We show that $p\to\sin_p(y)$ and $p\to\cos_p(y)$ are log-concave on the appropriate intervals while $p\to\tan_p(y)$ is…

Classical Analysis and ODEs · Mathematics 2014-02-17 D. B. Karp , E. G. Prilepkina

New perspectives, proofs, and some extensions of known results are presented concerning the behavior of the Fitzpatrick function of a monotone type operator in the general context of a locally convex space.

Functional Analysis · Mathematics 2017-12-27 M. D. Voisei

We establish higher order trace formulas for pairs of contractions along a multiplicative path generated by a self-adjoint operator in a Schatten-von Neumann ideal, removing earlier stringent restrictions on the kernel and defect operator…

Functional Analysis · Mathematics 2025-08-05 Arup Chattopadhyay , Chandan Pradhan , Anna Skripka

In this paper we study a class of Jacobi operators, such that each operator is generated by the unit Borel measure with a support consisting of a finite number of intervals on the real line R and a finite number of points in C, located…

Complex Variables · Mathematics 2013-10-17 Sergey Suetin

This paper studies Schauder theory to transmission problems modelled by fully nonlinear uniformly elliptic equations of second order. We focus on operators F that fails to be concave or convex in the space of symmetric matrices. In a first…

Analysis of PDEs · Mathematics 2024-04-26 G. C. Ricarte , C. S. Barroso , L. S. Tavares

In this paper, we introduce the concept of operator geometrically convex functions for positive linear operators and prove some Hermite-Hadamard type inequalities for these functions. As applications, we obtain trace inequalities for…

Functional Analysis · Mathematics 2015-08-14 Ali Taghavi , Vahid Darvish , Haji Mohammad Nazari , Sever S. Dragomir

We extend the well-known trace formula for Hill's equation to general one-dimensional Schr\"odinger operators. The new function $\xi$, which we introduce, is used to study absolutely continuous spectrum and inverse problems.

Spectral Theory · Mathematics 2008-02-03 Fritz Gesztesy , Helge Holden , Barry Simon , Zhong Xin Zhao

We point out the connection of the so-called H\^opital-style rules for monotonicity and oscillation to some well-known properties of concave/convex functions. From this standpoint, we are able to generalize the rules under no…

Classical Analysis and ODEs · Mathematics 2015-03-02 Man Kam Kwong

We begin by reviewing Zhu's theorem on modular invariance of trace functions associated to a vertex operator algebra, as well as a generalisation by the author to vertex operator superalgebras. This generalisation involves objects that we…

Representation Theory · Mathematics 2013-07-17 Jethro van Ekeren

In 1971 Fedi\u{i} proved the remarkable theorem that the linear second order partial differential operator in the plane with coefficients 1 and f^2 is hypoelliptic provided that f is smooth, vanishes at the origin and is positive otherwise.…

Classical Analysis and ODEs · Mathematics 2020-07-10 Lyudmila Korobenko , Eric T. Sawyer

Recently the behavior of operator monotone functions on unbounded intervals with respect to the relation of strictly positivity has been investigated. In this paper we deeply study such behavior not only for operator monotone functions but…

Functional Analysis · Mathematics 2017-09-26 M. Fujii , M. S. Moslehian , H. Najafi , R. Nakamoto

It is shown that, if nu >= 1/2 then the generalized Marcum Q function Q_nu(a, b) is log-concave in 0<=b <infty. This proves a conjecture of Sun, Baricz and Zhou (2010). We also point out relevant results in the statistics literature.

Statistics Theory · Mathematics 2011-05-31 Yaming Yu

We describe a type of n-point function associated to strongly regular vertex operator algebras V and their irreducible modules. Transformation laws with respect to the Jacobi group are developed for 1-point functions. For certain elements…

Quantum Algebra · Mathematics 2015-08-27 Matthew Krauel , Geoffrey Mason

This paper investigates the traces of functions belonging to the inhomogeneous Besov spaces B $\xi$ p,q , where $\xi$ is a product of capacities defined as powers of Gibbs measures. We first establish that the traces of functions in B $\xi$…

Functional Analysis · Mathematics 2026-03-27 Quentin Rible , Stéphane Seuret

This note deals with certain properties of convex functions. We provide results on the convexity of the set of minima of these functions, the behaviour of their subgradient set under restriction, and optimization of these functions over an…

Optimization and Control · Mathematics 2017-03-21 Miel Sharf , Daniel Zelazo

Under appropriate conditions, we obtain smoothness and convexity properties of $q$-scale functions for spectrally negative L\'evy processes. Our method appeals directly to very recent developments in the theory of potential analysis of…

Probability · Mathematics 2008-08-25 A. E. Kyprianou , V. Rivero , R. Song

We provide a necessary and sufficient condition for a simple object in a pivotal k-category to be ambidextrous. In turn, these objects imply the existence of nontrivial trace functions in the category. These functions play an important role…

Representation Theory · Mathematics 2011-12-21 Nathan Geer , Jonathan Kujawa , Bertrand Patureau-Mirand

We present some results on the monotonicity of some traces involving functions of self-adjoint operators with respect to the natural ordering of their associated quadratic forms. We also apply these results to complete a proof of the Wegner…

Functional Analysis · Mathematics 2016-09-14 J. -M. Combes , P. D. Hislop