Abstract Recently, the mean free path of ionizing photons in z = 6 intergalactic medium (IGM) was measured to be very short, presenting a challenge existing reionization models. At face value, measurement can interpreted as evidence that IGM clumps on scales M ≲ 10 8 ⊙ , key but largely untested prediction cold dark matter (CDM) paradigm. Motivated by this possibility, we study role underlying ...

Abstract Ultra-high-energy physics is about to enter a new era thanks the impressive results of experiments such as Large High Altitude Air Shower Observatory , detecting photons up $$1.4\times 10^{15}$$ 1.4 × 10 15 </mml:mat...

In this paper, we generalize White's regularity and structure theory for mean-convex mean curvature flow [45, 46, 48] to the setting with free boundary. A major new challenge in boundary is derive an a priori bound ratio between norm of second fundamental form curvature. We establish such via maximum principle triple-approximation scheme, which combines ideas from Edelen [9], Haslhofer-Hershkov...

It was recently argued that the geometric optics mean path length of rays inside a refractive object under Lambertian illumination is independent scattering strength medium [Savo et al., Science 358, 765 (2017)]. We here show it is, in fact, different case zero scattering. uncover and explain role trapped ray trajectories creating this unexpected discontinuity from to low This allows us derive ...

The Λand Ξ-hyperon mean free paths in nuclei are firstly calculated in the relativistic mean field (RMF) theory. The real parts of the optical potential are derived from the RMF approach, while the imaginary parts are obtained from those of nucleons with the relations: U IY S = ασY · U IN S and U IY V = αωY ·U IN V . With the assumption, the depth of the imaginary potential for Ξ − is WΞ ≃ − 3....