Department of Mathematics
Recent Submissions

Reproducing kernel kreĭn spaces
(Springer Basel, 2015)This chapter is an introduction to reproducing kernel Kre?in spaces and their interplay with operator valued Hermitian kernels. Existence and uniqueness properties are carefully reviewed. The approach used in this survey ... 
On the number of components of a complete intersection of real quadrics
(Springer Basel, 2012)Our main results concern complete intersections of three real quadrics. We prove that the maximal number B0 2 (N) of connected components that a regular complete intersection of three real quadrics in ℙN may have differs ... 
Toward a generalized shapiro and shapiro conjecture
(Springer Basel, 2012)We obtain a new, asymptotically better, bound g ≤ 1/4 d2 on the genus of a curve that may violate the generalized total reality conjecture. The bound covers all known cases except g = 0 (the original conjecture). © 2012, ... 
Ground states of onedimensional longrange ferromagnetic ising model with external field
(2012)A zerotemperature phasediagram of the onedimensional ferromagnetic Ising model is investigated. It is shown that at zero temperature spins of any compact collection of lattice points with identically oriented external ... 
A delayed consensus algorithm in networks of anticipatory agents
(Institute of Electrical and Electronics Engineers Inc., 2016)We introduce and analyze a delayed consensus algorithm as a model for interacting agents using anticipation of their neighbors' states to improve convergence to consensus. We derive a necessary and sufficient condition for ... 
Some asymptotics for extremal polynomials
(Springer New York LLC, 2016)We review some asymptotics for Chebyshev polynomials and orthogonal polynomials. Our main interest is in the behaviour of Widom factors for the Chebyshev and the Hilbert norms on small sets such as generalized Julia sets. ... 
On existence of an xintegral for a semidiscrete chain of hyperbolic type
(Institute of Physics Publishing, 2016)A class of semidiscrete chains of the form t1x = f (x,t,t1,tx) is considered. For the given chains easily verifiable conditions for existence of xintegral of minimal order 4 are obtained. © Published under licence by IOP ... 
Orthogonal Polynomials Associated with Equilibrium Measures on ℝ
(Springer Netherlands, 2017)Let K be a nonpolar compact subset of ℝ and μK denote the equilibrium measure of K. Furthermore, let Pn(⋅;μK) be the nth monic orthogonal polynomial for μK. It is shown that ∥Pn(⋅;μK)∥L2(μK), the Hilbert norm of Pn(⋅;μK) ... 
Orthogonal Polynomials on Generalized Julia Sets
(Birkhauser Verlag AG, 2017)We extend results by Barnsley et al. about orthogonal polynomials on Julia sets to the case of generalized Julia sets. The equilibrium measure is considered. In addition, we discuss optimal smoothness of Green’s functions ... 
Equivariant Moore spaces and the Dade group
(Academic Press Inc., 2017)Let G be a finite pgroup and k be a field of characteristic p. A topological space X is called an nMoore space if its reduced homology is nonzero only in dimension n. We call a GCWcomplex X an n_Moore Gspace over k ... 
Rank 3 finite pgroup actions on products of spheres
(Oxford University Press, 2016)Let $p$ be an odd prime. We prove that every rank 3 finite $p$group acts freely and smoothly on a product of three spheres. To construct this action, we first prove a generalization of a theorem of Lück and Oliver on ... 
Waring's problem with PiatetskiShapiro numbers
(Cambridge University Press, 2016)In this paper, we investigate in various ways the representation of a large natural number as a sum of a fixed power of PiatetskiShapiro numbers, thereby establishing a variant of the HilbertWaring problem with numbers ... 
Nonlocal Fordy–Kulish equations on symmetric spaces
(Elsevier B.V., 2017)We present nonlocal integrable reductions of the Fordy–Kulish system of nonlinear Schrodinger equations and the Fordy system of derivative nonlinear Schrodinger equations on Hermitian symmetric spaces. Examples are given ... 
Harmonic Besov spaces on the ball
(World Scientific Publishing Co. Pte Ltd, 2016)We initiate a detailed study of twoparameter Besov spaces on the unit ball of ℝn consisting of harmonic functions whose sufficiently highorder radial derivatives lie in harmonic Bergman spaces. We compute the reproducing ... 
The W 2 curvature tensor on warped product manifolds and applications
(World Scientific Publishing Co. Pte Ltd, 2016)The purpose of this paper is to study the W2curvature tensor on (singly) warped product manifolds as well as on generalized RobertsonWalker and standard static spacetimes. Some different expressions of the W2curvature ... 
Factorizations of Matrices over Projectivefree Rings
(World Scientific Publishing Co. Pte Ltd, 2016)An element of a ring R is called strongly J#clean provided that it can be written as the sum of an idempotent and an element in J#(R) that commute. In this paper, we characterize the strong J#cleanness of matrices over ... 
KerrSchildKundt metrics are universal
(Institute of Physics Publishing, 2017)We define (nonEinsteinian) universal metrics as the metrics that solve the sourcefree covariant field equations of generic gravity theories. Here, extending the rather scarce family of universal metrics known in the ... 
Friable values of piatetskishapiro sequences
(American Mathematical Society, 2017)We give various estimates for friable values of PiatetskiShapiro sequences. © 2017 American Mathematical Society. 
On the top degree of coinvariants
(Oxford University Press, 2017)For a finite group G acting faithfully on a finitedimensional Fvector space V, we show that in the modular case, the top degree of the vector coinvariants grows unboundedly: limm→∞ topdeg F[Vm]G = ∞. In contrast, in the ... 
The signature of a splice
(Oxford University Press, 2017)We study the behavior of the signature of colored links [6,9] under the splice operation. We extend the construction to colored links in integral homology spheres and show that the signature is almost additive, with a ...