We describe the image of the absolute Galois group acting on the pro-l completion of the fundamental group of the Gm minus Nth roots of unity. We relate the structure of the image with geometry and topology of modular varieties for the congruence subgroups 01(m; N ) of GLm(Z) for m = 1, 2, 3 . . . .

in this paper, we consider the finitely 2-generated groups k(s,l) and g_m as follows:k(s,l) = ;g_m = and find the explicit formulas for the probability of having nth-roots for them. also weinvestigate integers n for which, these groups are n-central.

here we consider all finite non-abelian 2-generator $p$-groups ($p$ an odd prime) of nilpotency class two and study the probability of having $n^{th}$-roots of them. also we find integers $n$ for which, these groups are $n$-central.

Let H be a separable, infinite dimensional complex Hilbert space and let B(H) be the algebra of bounded linear operators on H. An operator T∈ B(H) is said to be normal if T ∗T = TT ∗, subnormal if T is the restriction of a normal operator (acting on a Hilbert space K ⊇ H) to an invariant subspace, and hyponormal if T ∗T ≥ TT ∗. The Bram-Halmos criterion for subnormality states that an operator ...

In a recent paper [11], R.E. Curto, S.H. Lee and J. Yoon asked the following question. Let A be subnormal operator, assume that A2 is quasinormal. Does it follow quasinormal? this paper, we answer question in affirmative. fact, prove more general result nth roots of quasinormal operators are Research on problem has led us to new criterion for semispectral measure half-line spectral, written ter...