Department of Mathematics
Recent Submissions

Absolute continuity for operator valued completely positive maps on C* algebras
(American Institute of Physics, 20090211)Motivated by applicability to quantum operations, quantum information, and quantum probability, we investigate the notion of absolute continuity for operator valued completely positive maps on C* algebras, previously ... 
Closed Embeddings of Hilbert Spaces
(Elsevier, 20100901)Motivated by questions related to embeddings of homogeneous Sobolev spaces and to comparison of function spaces and operator ranges, we introduce the notion of closely embedded Hilbert spaces as an extension of that of ... 
Closely embedded Krein spaces and applications to Dirac operators
(Elsevier, 20110415)Motivated by energy space representation of Dirac operators, in the sense of K. Friedrichs, we recently introduced the notion of closely embedded Krein spaces. These spaces are associated to unbounded selfadjoint operators ... 
Constructing modular separating invariants
(Elsevier, 20091201)We consider a finite dimensional modular representation V of a cyclic group of prime order p. We show that two points in V that are in different orbits can be separated by a homogeneous invariant polynomial that has degree ... 
Random walks on symmethric spaces and inequalities for matrix spectra
(Elsevier, 20001101)Using harmonic analysis on symmetric spaces we reduce the singular spectral problem for products of matrices to the recently solved spectral problem for sums of Hermitian matrices. This proves R.C. Thompson’s conjecture ... 
On construction of recursion operators from Lax representation
(American Institute of Physics, 199912)In this work we develop a general procedure for constructing the recursion operators for nonlinear integrable equations admitting Lax representation. Several new examples are given. In particular, we find the recursion ... 
Set covering and Serre's theorem on the cohomology algebra of a pgroup
(Elsevier, 2001111)We define a group theoretical invariant, denoted by s(G), as a solution of a certain set covering problem and show that it is closely related to chl(G), the cohomology length of a pgroup G. By studying s(G) we improve the ... 
On contractibility of th orbit space of a Gposet of Brauer pairs
(Elsevier, 19990215)Given apblockbof a finite groupG, we show that theGposet of Brauer pairs strictly containing (1,b) has contractibleGorbit space. A similar result is proved for certainGposets ofpsubgroups. Both results generalise P. ... 
Integrable Equations on Time Scales
(, 2005)Integrable systems are usually given in terms of functions of continuous variables (on R), in terms of functions of discrete variables (on Z), and recently in terms of functions of q variables (on Kq). We formulate the ... 
Discretization of hyperbolic type Darboux integrable equations preserving integrability
(American Institute of Physics, 2011)A method of integrable discretization of the Liouville type nonlinear partial differential equations based on integrals is suggested. New examples of the discrete Liouville type models are presented. © 2011 American Institute ... 
Infinite products of finite simplegroups
(, 1996)We classify the sequences hSn j n 2 Ni of nite simple nonabelian groups such that Q n Sn has uncountable co nality. 
Some identities and asymptotics for characters of the symmetric group
(Elsevier, 19980815) 
Boundary Value Problems for Integrable equations compatible with the symmetry algebra
(American Institute of Physics, 1995)Boundary value problems for integrable nonlinear partial differential equations are considered from the symmetry point of view. Families of boundary conditions compatible with the HarryDym, KdV, and mKdV equations and ... 
Duality for Ideals in the Grassmann Algebra
(Elsevier, 19960701)A duality is established between left and right ideals of a finite dimensional Grassmann algebra such that if under the duality a left ideal I and a right ideal J correspond then I is the left annihilator of J and J the ... 
Backlund transformations for discrete Painleve equations: Discrete PIIPV
(Elsevier, 2006)Transformation properties of discrete Painleve´ equations are investigated by using an algorithmic method. This method yields explicit transformations which relates the solutions of discrete Painleve´ equations, discrete ... 
Integrable coupled KdV systems
(American Institute of Physics, 199804)We give the conditions for a system of Ncoupled Korteweg de Vries (KdV) type of equations to be integrable. We find the recursion operators of each subclass and give all examples for N=2. © 1998 American Institute of Physics. 
Variable coefficient third order Kortewegde Vries type of equations
(American Institute of Physics, 1995)It is shown that the integrable subclasses of the equations q,t=f(x,t)q,s +H(x,t,q,q,,) are the same as the integrable subclasses of the equations q,t= q,3 + F(q,q, *). 0 1995 American Institute of Physics. Classification 
A mixture representation of the Linnik distribution
(Elsevier, 199601)Linnik distribution with the characteristic function ~o,(tl = 1/(1 + Itl=), 0 < ~ < 2, is shown to possess the following property. Let X,,Xp be random variables possessing the Linnik distribution with parameters ~ and (0 ... 
http://dx.doi.org/10.1006/jabr.1994.1070
(Elsevier, 19940301) 
Equivariant CWcomplexes and the orbit category
(, 2013)We give a general framework for studying GCW complexes via the orbit category. As an application we show that the symmetric group G D S5 admits a finite GCW complex X homotopy equivalent to a sphere, with cyclic isotropy ...