General RM Rings

Left dihedral codes over Galois rings ${\rm GR}(p^2,m)$

Let D2n = 〈x, y | x = 1, y = 1, yxy = x〉 be a dihedral group, and R = GR(p, m) be a Galois ring of characteristic p and cardinality p where p is a prime. Left ideals of the group ring R[D2n] are called left dihedral codes over R of length 2n, and abbreviated as left D2n-codes over R. Let gcd(n, p) = 1 in this paper. Then any left D2n-code over R is uniquely decomposed into a direct sum of conca...

Tate Cohomology over Fairly General Rings

Tate cohomology was originally defined over finite groups. More recently, Avramov and Martsinkovsky showed how to extend the definition so that it now works well over Gorenstein rings. This paper improves the theory further by giving a new definition that works over more general rings, specifically, those with a dualizing complex. The new definition of Tate cohomology retains the desirable prop...

Topological superconductor in quasi-one-dimensional ${\rm Tl}_{2-x}{\rm Mo}_6{\rm Se}_6$

Identifying an Honest ${\rm EXP}^{\rm NP}$ Oracle Among Many

We provide a general framework to remove short advice by formulating the following computational task for a function f : given two oracles at least one of which is honest (i.e. correctly computes f on all inputs) as well as an input, the task is to compute f on the input with the help of the oracles by a probabilistic polynomial-time machine, which we shall call a selector. We characterize the ...

Bank ownership, rm value and rm capital structure in Europe*

We investigate the role of banks in the ownership structure of non-…nancial …rms. Distinguishing between banks and other institutional investors as shareholders, we examine the relationship between …nancial institution ownership and the performance of the …rms in which they hold equity. We control explicitly for the capital structure decision of the …rms and the ownership decision of …nancial i...