In this paper we study the properties of derivations of A B, where A and B are simple separable C*-algebras, and A B is the C*-completion of A B with respect to a C*-norm Yon A B and we will characterize the derivations of A B in terms of the derivations of A and B

the divisibility graph $mathscr{d}(g)$ for a finite group $g$ is a graph with vertex set ${rm cs}(g)setminus{1}$‎ ‎where ${rm cs}(g)$ is the set of conjugacy class sizes of $g$‎. ‎two vertices $a$ and $b$ are adjacent whenever $a$ divides‎ ‎$b$ or $b$ divides $a$‎. ‎in this paper we will find the number of connected components of $mathscr{d}(g)$ where $g$ is a‎ ‎simple zassenhaus group or an sp...

Let $k$ be field of characteristic $p$, andlet $G$ be any finite group with splitting field $k$. Assume that $B$ is a $p$-block of $G$.In this paper, we introduce the notion of radical $B$-chain $C_{B}$, and we show that the $p$-local rank of $B$ is equals the length of $C_{B}$. Moreover, we prove that the vertex of a simple $kG$-module $S$ is radical if and only if it has the same vertex of th...

in this paper we study the properties of derivations of a b, where a and b are simple separable c*-algebras, and a b is the c*-completion of a b with respect to a c*-norm yon a b and we will characterize the derivations of a b in terms of the derivations of a and b

We prove the relation between the triangulated categories of graded B-branes on simple singularities and the derived categories of representations of Dynkin quivers. The proof is based on the theory of weighted projective lines by Geigle and Lenzing and Orlov’s theorem on the relation between triangulated categories of graded B-branes and the derived category of coherent sheaves.