We investigate manifolds obtained as a quotient of a doubly warped product. We show that they are always covered by the product of two suitable leaves. This allows us to prove, under regularity hypothesis, that these manifolds are a doubly warped product up to a zero measure subset formed by an union of leaves. We also obtain a necessary and sufficient condition which ensures the decomposition ...

Let ; and n be point processes and let p€[O,I]. We say that ; is a p-thinning of n, if it is obtained from n by deleting the atoms independently with probability l-p. It is shown that, if PI,P2, ... €(O,I] with P +0 n and if ; n is a p -thinning of some n for each n€N, then ~n converges in distribution in the vague topology if and only if Pnnn does. Furthermore, denoting the limits by ~ and n r...

The distributed averaging problem is to devise a protocol which will enable the members of a group of n > 1 agents to asymptotically determine in a decentralized manner, the average of the initial values of their scalar agreement variables. A typical averaging protocol can be modeled by a linear iterative equation whose update matrices are doubly stochastic. Building on the ideas proposed in [1...

We describe maximal nilpotent subsemigroups of a given nilpotency class in the semigroup Ωn of all n × n real matrices with nonnegative coefficients and the semigroup Dn of all doubly stochastic real matrices.

Let A ∈ Ωn be doubly-stochastic n × n matrix. Alexander Schrijver proved in 1998 the following remarkable inequality per(Ã) ≥ ∏ 1≤i,j≤n (1−A(i, j)); Ã(i, j) =: A(i, j)(1−A(i, j)), 1 ≤ i, j ≤ n (1) We prove in this paper the following generalization (or just clever reformulation) of (1): For all pairs of n × n matrices (P,Q), where P is nonnegative and Q is doublystochastic log(per(P )) ≥ ∑ 1≤i,...

Let $Rin textbf{C}^{mtimes m}$ and $Sin textbf{C}^{ntimes n}$ be nontrivial involution matrices; i.e., $R=R^{-1}neq pm~I$ and $S=S^{-1}neq pm~I$. An $mtimes n$ complex matrix $A$ is said to be an $(R, S)$-symmetric ($(R, S)$-skew symmetric) matrix if $RAS =A$ ($ RAS =-A$). The $(R, S)$-symmetric and $(R, S)$-skew symmetric matrices have a number of special properties and widely used in eng...

Two concepts of symmetry for the distributions of positive random variables Y are log-symmetry (symmetry of the distribution of log Y ) and Rsymmetry (Mudholkar & Wang, 2007). In this paper, we characterise the distributions that have both properties, which we call doubly symmetric. It turns out that doubly symmetric distributions constitute a subset of those distributions that are moment-equiv...