5 papers
A note on real operator monotone functions
Marcell Gaál, Miklós Pálfia
In this paper we initiate the study of real operator monotonicity for functions of tuples of operators, which are multivariate structured maps with a functional calculus called fre…
On the existence of an extremal function in the delsarte extremal problem
Marcell Gaál, Zsuzsanna Nagy-Csiha
This paper is concerned with a Delsarte type extremal problem. Denote by the set of positive definite continuous functions on a locally compact abelian group .…
Minimal energy point systems on the unit circle and the real line
Marcell Gaál, Béla Nagy, Zsuzsanna Nagy-Csiha +1
In this paper, we investigate discrete logarithmic energy problems in the unit circle. We study the equilibrium configuration of electrons and pairs of external protons o…
Integral comparisons of nonnegative positive definite functions on LCA groups
Marcell Gaál, Szilárd Gy. Révész
In this paper we investigate the following questions. Let be two regular Borel measures of finite total variation. When do we have a constant satisfying $$\int f dν\le C…
On isometry groups of self-adjoint traceless and skew-symmetric matrices
Marcell Gaál, Robert M. Guralnick
This note is concerned with isometries on the spaces of self-adjoint traceless matrices. We compute the group of isometries with respect to any unitary similarity invariant norm. T…