Let R be an arbitrary ring with identity. In this paper, we introduce quasi-reduced rings as a generalization of reduced rings and investigate their properties. The ring R is called quasi-reduced if for any a, b ∈ R, ab = 0 implies (aR) ∩ (Rb) is contained in the center of R. We prove that some results of reduced rings can be extended to quasi-reduced rings for this general settings. 2010 Mathe...

We study the ideals of the rational cohomology ring of the Hilbert scheme X [n] of n points on a smooth projective surface X . As an application, for a large class of smooth quasi-projective surfaces X , we show that every cup product structure constant of H∗(X ) is independent of n; moreover, we obtain two sets of ring generators for the cohomology ring H∗(X ). Similar results are established ...

An R-module M is called epi-retractable if every submodule of MR is a homomorphic image of M. It is shown that if R is a right perfect ring, then every projective slightly compressible module MR is epi-retractable. If R is a Noetherian ring, then every epi-retractable right R-module has direct sum of uniform submodules. If endomorphism ring of a module MR is von-Neumann regular, then M is semi-...

A ΣΠΣΠ(k) circuit C = ∑k i=1 Fi = ∑k i=1 ∏di j=1 fij is unmixed if for each i ∈ [k], Fi = fi1(x1) · · · fin(xn), where each fij is a univariate polynomial given in the sparse representation. In this paper, we give a polynomial time black-box algorithm of identity testing for the low degree unmixed ΣΠΣΠ(k) circuits. In order to obtain the black-box algorithm, we first show that a special class o...

We demonstrate a silicon photonic platform using thin buried oxide silicon-on-insulator (SOI) substrates using localized substrate removal. We show high confinement silicon strip waveguides, micro-ring resonators and nanotapers using this technology. Propagation losses for the waveguides using the cutback method are 3.88 dB/cm for the quasi-TE mode and 5.06 dB/cm for the quasi-TM mode. Ring res...

Let $R$ be a right artinian ring or a perfect commutative‎‎ring‎. ‎Let $M$ be a noncosingular self-generator $sum$-lifting‎‎module‎. ‎Then $M$ has a direct decomposition $M=oplus_{iin I} M_i$‎,‎where each $M_i$ is noetherian quasi-projective and each‎‎endomorphism ring $End(M_i)$ is local‎.

Frobenius algebras play an important role in the representation theory of finite groups. In the present work, we investigate the (quasi) Frobenius property of n-group algebras. Using the (quasi-) Frobenius property of ring, we can obtain some information about constructions of module category over this ring ([2], p. 66–67).