The family of regular closed subsets of a topological space is used to introduce two concepts concerning a function f from a space X to a space Y . The first of them is the notion of f being rc-continuous. One of the established results states that a space Y is extremally disconnected if and only if each continuous function from a space X to Y is rc-continuous. The second concept studied is the...

We discuss the number variance 2 (L) and the spectral form factor F() of the energy levels of bound quantum systems whose classical counterparts are strongly chaotic. Exact periodic{orbit representations of 2 (L) and F() are derived which explain the breakdown of universality, i. e., the deviations from the predictions of random{matrix theory. The relation of the exact spectral form factor F() ...

Let C be nonempty closed convex subset of real Hilbert space H. Consider C a nonexpansive semigroup I {T s : s ≥ 0}with a common fixed point, a contraction f with coefficient 0 < α < 1, and a strongly positive linear bounded operator A with coefficient γ > 0. Let 0 < γ < γ/α. It is proved that the sequence {xn} generated iteratively by xn I − αnA 1/tn ∫ tn 0 T s ynds αnγf xn , yn I − βnA xn βnγ...

Numerical approximations of strongly degenerate variational problems of the form J(u) = /J F{u') + (u f)2 are considered, where F is assumed convex but may have intervals where F" = 0. It is shown that, in spite of the degeneracy, natural numerical approximations still converge in Wx -p . Rates in weaker norms and the connection with nonconvex variational problems are also considered.

We study strong solutions u : R → X, a Banach space X, of the nth-order evolution equation u(n) −Au(n−1) = f , an infinitesimal generator of a strongly continuous group A : D(A) ⊆ X → X, and a given forcing term f : R → X. It is shown that if X is reflexive, u and u(n−1) are Stepanov-bounded, and f is Stepanov almost periodic, then u and all derivatives u′, . . . ,u(n−1) are strongly almost per...

In real Hilbert spaceH , from an arbitrary initial point x0 ∈H , an explicit iteration scheme is defined as follows: xn+1 = αnxn + (1 − αn)Tn+1xn,n ≥ 0, where Tn+1xn = Txn − λn+1μF(Txn), T :H →H is a nonexpansive mapping such that F(T) = {x ∈ K : Tx = x} is nonempty, F :H →H is a η-strongly monotone and k-Lipschitzian mapping, {αn} ⊂ (0,1), and {λn} ⊂ [0,1). Under some suitable conditions, the ...

Let $f:A\rightarrow B$ be a ring homomorphism and $K$ an ideal of $B$. Many variations the notions clean nil-clean rings have been studied by variety authors. We investigate strongly $\pi$-regular clean-like properties amalgamation $A\bowtie^{f}K$ $A$ with $B$ along respect to $f$.

Let f(n) be a strongly additive complex-valued arithmetic function. Under mild conditions on f , we prove the following weighted strong law of large numbers: if X, X1, X2, . . . is any sequence of integrable i.i.d. random variables, then lim N→∞ ∑N n=1 f(n)Xn ∑N n=1 f(n) = EX a.s.

For analytic functions f (z) = z p +a p+1 z p+1 +··· in the open unit disk U and a polynomial Q(z) of degree n > 0, the function F(z) = f (z)[Q(z)] β/n is introduced. The object of the present paper is to determine the radius of p-valently strongly starlikeness of order γ for F(z).

In this paper, we prove that a linear action of a reductive group on a polynomial ring with good ltrations over a eld of characteristic p > 0 yields a strongly F-regular (in particular, Cohen-Macaulay) invariant subring. The strongly F-regular property of some known examples of invariant subrings, such as the coordinate rings of Schubert varieties in Grassmannians, are recovered. A similar resu...