Consider a measure-preserving action Γ y (X,μ) of a countable group Γ and a measurable cocycle α : X × Γ → Aut(Y ) with countable image, where (X,μ) is a standard Lebesgue space and (Y, ν) is any probability space. We prove that if the Koopman representation associated to the action Γ y X is non-amenable, then there does not exist a countable-to-one Borel homomorphism from the orbit equivalence...

purpose: to report an extremely rare presentation of isolated orbital xanthogranuloma with no systemic disease, nor dermatologic manifestation. case report: the patient was a 45-year-old man complaining of a mass lesion in the superior and inferior eyelids of his right eye; the lesions had been enlarging slowly and painlessly since 5 years before. other examinations (including skin, heart, etc....

We have studied the ionization of Rydberg wave packets by subpicosecond, nearly unipolar electromagnetic field pulses, in the regime where the duration of the electric field is less than the classical Kepler orbit time 2pn3 for the wave packet. In contrast to the subpicosecond optical pulses, subpicosecond field pulses can ionize wave packets when the probability density near the inner turning ...

First-principles calculations of the essential spin-orbit and spin relaxation properties of phosphorene are performed. Intrinsic spin-orbit coupling induces spin mixing with the probability of b2 ≈ 10−4, exhibiting a large anisotropy, following the anisotropic crystalline structure of phosphorene. For realistic values of the momentum relaxation times, the intrinsic (Elliott-Yafet) spin relaxati...

The Open University, in collaboration with e2v technologies Ltd and XCAM Ltd, have been selected to fly an experimental payload on board the UK Space Agency's UKube-1 pilot Cubesat programme. Cubesat payloads offer a unique opportunity to rapidly build and fly space hardware for minimal cost, providing easy access to the space environment. The proposed payload incorporated new imaging technolog...

We study the recovery results of lp-constrained compressive sensing (CS) with p ≥ 1 via robust width property and determine conditions on the number of measurements for standard Gaussian matrices under which the property holds with high probability. Our paper extends the existing results in Cahill and Mixon (2014) from l2-constrained CS to lp-constrained case with p ≥ 1 and complements the reco...

We look at the process of inheritance of mitochondrial DNA as a percolation model on trees equivalent to the Galton-Watson process. The model is exactly solvable for its percolation threshold pc and percolation probability critical exponent. In the approximation of small percolation probability, and assuming limited progeny number, we are also able to find the maximum and minimum percolation pr...

in this paper, we consider scheduling of project networks under minimization of total weighted resource tardiness penalty costs. in this problem, we assume constrained resources are renewable and limited to very costly machines and tools which are also used in other projects and are not accessible in all periods of time of a project. in other words, there is a dictated ready date as well as a d...

In this paper, we consider an M/G/1 retrial queue with Bernoulli feedback and general retrial times where the external arrivals blocked either with probability q join the infinite waiting room called non-retrial queue or with probability p, (p+q = 1) leave the service area and enter the retrial group called orbit in FIFO discipline. Also we assume that only the customer at the head of the orbit...