In the present we introduce a concept of doubly stochastic quadratic operator. We prove necessary and sufficient conditions for doubly stochasticity of operator. Besides, we prove that the set of all doubly stochastic operators forms convex polytope. Finally, we study analogue of Birkhoff’s theorem for the class of doubly stochastic operators. Mathematics Subject Classification: 15A51, 15A63, 4...

We report the first conformal ultra-wide band (UWB) array on a doubly curved surface for wide angle electronic scanning. use quadrilateral mesh as basis systematically arraying UWB radiators arbitrary surfaces. A prototype consisting of 52 element, dual-polarized Vivaldi arranged over 181 mm diameter hemisphere is developed. The antennas and SMP connectors are 3D printed out titanium to allow s...

In the present note we study the existence or non-existence of doubly warped and doubly twisted product CR-submanifolds in nearly Kaehler manifolds.

Let Ωn denote the set of all n × n doubly stochastic matrices. Two unequal matrices A and B in Ωn are called permanental mates if the permanent function is constant on the line segment t A + (1 − t)B, 0 ≤ t ≤ 1, connecting A and B. We study the perturbation matrix A + E of a symmetric matrix A in Ωn as a permanental mate of A. Also we show an example to disprove Hwang’s conjecture, which states...

We study a hedging and pricing problem of a model where the price process of a risky asset has jumps with instantaneous feedback from the most recent asset price. We model these jumps with a doubly stochastic Poisson process with an intensity function depending on the current price. We find a closed form expression of the local risk minimization strategy using Föllmer and Schweizer decompositio...

An analytical investigation on the nonlinear response of doubly curved panels constructed from homogeneous face sheets and carbon nanotube reinforced composite (CNTRC) core subjected to external pressure in thermal environments is presented this paper. Carbon nanotubes (CNTs) are into layer through uniform or functionally graded distributions. The properties constituents assumed be temperature ...