Related papers: Dynamical Friction in Superfluids
Dynamical friction arises from the interaction of a perturber and the gravitational wake it excites in the ambient medium. This interaction is usually derived assuming that the perturber has a constant velocity. In realistic situations,…
Any gravitating mass traversing a relatively sparse gas experiences a retarding force created by its disturbance of the surrounding medium. In a previous contribution (Lee & Stahler 2011), we determined this dynamical friction force when…
The supersonic motion of gravitating objects through a gaseous medium constitutes a classical problem in theoretical astrophysics. Its application covers a broad range of objects and scales from planets up to galaxies. Especially the…
The dynamical friction force experienced by a massive gravitating body moving through a gaseous medium is modified by sufficiently strong large-scale magnetic fields. Using linear perturbation theory, we calculate the structure of the wake…
Recent work has suggested that the net gravitational force acting on a massive and luminous perturber travelling through a gaseous and opaque medium can have same direction as the perturber's motion (an effect sometimes called negative…
Using time-dependent linear perturbation theory, we evaluate the dynamical friction force on a massive perturber M_p traveling at velocity V through a uniform gaseous medium of density rho_0 and sound speed c_s. This drag force acts in the…
Using high-resolution, two-dimensional hydrodynamic simulations, we investigate nonlinear gravitational responses of gas to, and the resulting drag force on, a very massive perturber M_p moving at velocity V_p through a uniform gaseous…
When a gravitating point mass moves subsonically through a magnetized and isothermal medium, the dynamical structure of the flow is studied far from the mass using a perturbation analysis. Analytical solutions for the first-order density…
When a gravitating object moves across a given mass distribution, it creates an overdense wake behind it. Here, we performed an analytical study of the structure of the flow far from object when the flow is isentropic and the object moves…
We study the force of dynamical friction acting on a gravitating point mass that travels through an extended, isothermal gas. This force is well established in the hypersonic limit, but remains less understood in the subsonic regime. Using…
We consider the gravitational force exerted on a point-like perturber of mass $M$ travelling within a uniform gaseous, opaque medium at constant velocity $V$. The perturber irradiates the surrounding gas with luminosity $L$. The diffusion…
We investigate diffusion in supersonic, turbulent, compressible flows. Supersonic turbulence can be characterized as network of interacting shocks. We consider flows with different rms Mach numbers and where energy necessary to maintain…
We present an analytic approach to the dynamical friction (DF) acting on a circularly moving point mass perturber in a gaseous medium. We demonstrate that, when the perturber is turned on at $t=0$, steady-state (infinite time perturbation)…
Wearless friction is investigated in a simple mechanical model called Frenkel-Kontorova-Tomlinson model. We have introduced this model in [Phys. Rev. B, Vol. 53, 7539 (1996)] where the static friction has already been considered. Here the…
In this article, we calculate the friction between two counter-flowing bosonic and fermionic super-fluids. In the limit where the boson-boson and boson-fermion interactions can be treated within the mean-field approximation, we show that…
It is shown that the standard effective field theory of non-relativistic superfluids, which includes only the leading order action in derivative expansion, is in general inadequate for studying supersonic processes. Namely, for a proper…
We study dynamical friction in interacting relativistic systems with arbitrary mean free paths and medium constituent masses. Our novel framework recovers the known limits of ideal gas and ideal fluid when the mean free path goes to…
We analyze the effect of a gravitational field on the sound modes of superfluids. We derive an instability condition that generalizes the well known Jeans instability of the sound mode in normal fluids. We discuss potential experimental…
We consider the hydrodynamics of supersymmetric fluids. Supersymmetry is broken spontaneously and the low energy spectrum includes a fermionic massless mode, the $\mathit{phonino}$. We use two complementary approaches to describe the…
We perform particle-resolved simulations of subsonic and transonic flows past random arrays of spherical particles. The Reynolds number is held at $Re{\approx}300$ to ensure the flow remains in the continuum regime. At low volume fractions,…