Conditions are given which guarantee that the k-subdirect sum of S-strictly diagonally dominant matrices (S-SDD) is also S-SDD. The same situation is analyzed for SDD matrices. The converse is also studied: given an SDD matrix C with the structure of a k-subdirect sum and positive diagonal entries, it is shown that there are two SDD matrices whose subdirect sum is C. AMS subject classifications...

‎in a real hilbert space‎, ‎an iterative scheme is considered to‎ ‎obtain strong convergence which is an essential tool to find a‎ ‎common fixed point for a countable family of nonexpansive mappings‎ ‎and the solution of a variational inequality problem governed by a‎ ‎monotone mapping‎. ‎in this paper‎, ‎we give a procedure which results‎ ‎in developing shehu's result to solve equilibrium prob...

We consider the analytic properties of Bioch Hamiltonians and their energy levels as functions of quasi-momentum k. Among other results are: (1) The only entire band is the trivial free electron parabola. (2) The only isolated singularities allowed are branch points. (3) In one dimension, no natural boundaries or logarithmic branch points occur. (4) The periodic attractive screened Coulomb latt...

We employ positivity of Riesz functionals to establish representing measures (or approximate representing measures) for truncated multivariate moment sequences. For a truncated moment sequence y, we show that y lies in the closure of truncated moment sequences admitting representing measures supported in a prescribed closed set K ⊆ R if and only if the associated Riesz functional Ly is K-positi...

We prove a version of Schur–Weyl duality over finite fields. We prove that for any field k, if k has at least r + 1 elements, then Schur– Weyl duality holds for the rth tensor power of a finite dimensional vector space V . Moreover, if the dimension of V is at least r + 1, the natural map kSr → EndGL(V )(V ) is an isomorphism. This isomorphism may fail if dimk V is not strictly larger than r.

Resting tryosinase was diamagnetic between 1.4 K and 200 K. Redox titration showed that it, but not apotyrosinase, contained a titrable group, E’, = $0.36 volt (pH 7.0), R = 2. Upon denaturation with acid under strictly anaerobic conditions, the EPR-detectable copper increased from less than 5 % of the copper present to about 100%. It is concluded that the active site of the enzyme contains a p...

In [GM] a Banach space X was constructed such that every operator from a subspace Y ⊂ X into the space is of the form λIY→X +S, where IY→X is the inclusion map and S is strictly singular. In this paper we show that there is an operator T from a subspace Y ⊂ X into X which is not of the form λIY→X + K with K compact.

We consider several natural classes of committee scoring rules, namely, weakly separable, representation-focused, top-k-counting, OWAbased, and decomposable rules. We study some of their axiomatic properties, especially properties of monotonicity, and concentrate on containment relations between them. We characterize SNTV, Bloc, and k-approval Chamberlin–Courant, as the only rules in certain in...

We prove the absence of non-scattering energies for potentials in the plane having a corner of angle smaller than π. This extends the earlier result of Bl̊asten, Päivärinta and Sylvester who considered rectangular corners. In three dimensions, we prove a similar result for any potential with a circular conic corner whose opening angle is outside a countable subset of (0, π).