We address the following inverse problem in quantum statistical physics: does the quantum free energy (von Neumann entropy + kinetic energy) admit a unique minimizer among the density operators having a given local density n(x)? We give a positive answer to that question, in dimension one. This enables to define rigourously the notion of local quantum equilibrium, or quantum Maxwellian, which i...

static properties, relatively intensity noise and intensity modulation response in quantum cascade lasers (qcls) studied theoretically in this paper. the present rate equations model consists of three equations for the electrons density in the conduction band and one equation for photons density in cavity length. two equations were derived to calculate the noise and modulation response. calcula...

It is shown that the α−dynamo of Magnetohydrodynamics, the hydrodynamic Squire equation as well as an interpolation model of PT −symmetric Quantum Mechanics are closely related as spectral problems in Krein spaces. For the α−dynamo and the PT −symmetric model the strong similarities are demonstrated with the help of a 2 × 2 operator matrix representation, whereas the Squire equation is re-inter...

The decay of quantum vortex rings in counterflow regimes, visualized Helium II with the help solid hydrogen particles trapped to their cores, has been a puzzling issue within usual description superfluid dynamics, grounded on hypothesis that filament is, effectively, an extended massless object subject canceling superposition Magnus and mutual friction forces. We discuss, from general energy-bu...

The commonly used linear k-ε turbulence model is shown to be incapable of accurate prediction of turbulent flows, where non-isotropy is dominant. Two examples of non-isotropic flows, which have a wide range of applications in marine waters, are saline water flow and the stratified flows due to temperature gradients. These relate to stratification and consequently, variation of density through...

An accurate description of the optical response subwavelength metallic particles and nanogap structures is a key problem plasmonics. Quantum hydrodynamic theory (QHT) has emerged as powerful method to calculate nanoparticles (NPs) since it takes into account nonlocality spill-out effects. Nevertheless, absorption spectra NPs obtained with conventional QHT, i.e., incorporating Thomas-Fermi (TF) ...