We consider the Riemann problem for relativistic flows of polytropic fluids and find relations for the flow characteristics. Evolution of physical quantities takes especially simple form for the case of cold magnetized plasmas. We find exact explicit analytical solutions for one-dimensional expansion of magnetized plasma into vacuum, valid for arbitrary magnetization. We also consider expansion...

Extreme weather events such as heat waves and cold spells affect people’s lives. This study develops a probabilistic framework to evaluate spells. As case studies, average daily temperatures of meteorological stations the two cities (Tehran Vancouver) from 1995 2016 are used identify four main indicators including intensity, duration, rate occurrence. In addition, spatial analysis is obtained t...

A theory of Rydberg atom interactions is used to derive analytical forms for the spin-wave pair correlation function in laser-excited cold-atom vapors. This function controls the quantum statistics of light emission from dense, inhomogeneous clouds of cold atoms of various spatial dimensionalities. The results yield distinctive scaling behaviors on the microsecond time scale, including generali...

In the Mediterranean basin, the globally increasing temperatures are expected to be accompanied by longer heat waves. Commonly assumed to benefit cold-limited invasive alien species, these climatic changes may also change their feeding preferences, especially in the case of omnivorous ectotherms. We investigated heat wave effects on diet choice, growth and energy reserves in the invasive red sw...

Recently, p-wave cold collisions were shown to dominate the density-dependent shift of the clock transition frequency in a 171Yb optical lattice clock. Here we demonstrate that by operating such a system at the proper excitation fraction, the cold-collision shift is canceled below the 5 × 10−18 fractional frequency level. We report inelastic two-body loss rates for P0 -P0 and S0 -P0 scattering....