Entanglement Entropy of Free Fermions with a Random Matrix as a One-Body Hamiltonian.

We consider a quantum system of large size and its subsystem of size , assuming that is much larger than , which can also be sufficiently large, i.e., 1≪L≲N.

Drag reduction of three-dimensional bodies by base blowing with various gas densities.

This study reveals that injecting a light fluid of density ρ_{b} in the recirculating bubble of a bluff body at Re≈6.4×10^{4} has a greater drag reduction potential than blowing fluid of a density greater than or equal to that of the free stream ρ. It is found that the maximum drag reduction scales as (ρ_{b}/ρ)^{-1/6}.

Quasiperiodic routes to chaos in confined two-dimensional differential convection.

The complete cascade of bifurcations from steady to chaotic convection, as the Rayleigh number is varied, is considered numerically inside an air-filled differentially heated cavity. The system is assumed to be two-dimensional and is invariant under a generalized reflection about the center of the cavity. In the neighborhood of several codimension-two points, two main routes emerge, characterized by different symmetries of the first oscillatory eigenstate.

Imperfect supercritical bifurcation in a three-dimensional turbulent wake.

The turbulent wake of a square-back body exhibits a strong bimodal behavior. The wake randomly undergoes symmetry-breaking reversals between two mirror asymmetric steady modes [reflectional symmetry-breaking (RSB) modes]. The characteristic time for reversals is about 2 or 3 orders of magnitude larger than the natural time for vortex shedding.

Frequency-selection mechanism in incompressible open-cavity flows via reflected instability waves.

We present an alternative perspective on nonharmonic mode coexistence, commonly found in the shear layer spectrum of open-cavity flows. Modes obtained by a local linear stability analysis of perturbations to a two-dimensional, incompressible, and inviscid sheared flow over a cavity of finite length and depth were conditioned by a so-called coincidence condition first proposed by Kulikowskii [J. Appl.