Relativistic MHD Shock
The energy momentum tensor for a relativistic pressureless fluid is $$T^{\mu\nu} = (\rho h + \frac{b^2}{4\pi})u^\mu u^\nu + \frac{b^2}{8\pi}g^{\mu\nu} - \frac{b^\mu …
Note on Electrodynamics
Particle Motion in Uniform Perpendicular Electromagnetic Fields A test particle with mass $m$ and charge $q$ moving at velocity $\boldsymbol{v}$ in an electromagnetic field feels …
MHD Turbulence Cascade
Consider the ideal incompressible MHD wave governed by the equations $$\begin{aligned} \frac{\partial \vec{v}}{\partial t}+\vec{v}\cdot \nabla\vec{v}&=&\vec{B}\cdot\nabla\vec{B}\\ …
Magnetic Fields in Relativistic MHD
In relativistic MHD, the magnetic field 4-vector $b_\mu$ and electric field $e_\mu$ in the fluid frame is defined through the 4-vector $u^{\mu}$ and EM 2-form $F_{\mu\nu}$.
Eliminating Pressure for Incompressible MHD
In the formulation of Elsasser’s variables $\mathbf{U} = \mathbf{v}+\mathbf{b}$ and $\mathbf{W} = \mathbf{v}-\mathbf{b}$, $$\begin{aligned} &&\partial_t \mathbf{U} = …
Conservation of Topological Quantities in Euler Equation
The fluid equations in the conservative form are $$\begin{aligned} \partial_t \rho +\nabla\cdot(\rho \boldsymbol{u})&=&0 \\ \partial_t (\rho u^i)+\nabla\cdot(\rho …
Electromagnetic Signatures of Supermassive Binary Black Holes. I. Thermal Synchrotron, Self-Lensing Flares, and Jet Precession
First image of supermassive black hole binary.
hong-xuan-jiang
MicroTidal Disruption Events at Galactic Centers
What may happen when a black hole collides with a white dwarf?
The effects of star-gas interactions on binary evolution in open clusters
Star-gas interactions can provide gravitational feedback that influences the dynamical evolution of stellar clusters, through processes such as dynamical friction (DF) and its …
jixuan-yang
Black Hole Collisions with Thin Accretion Disks: OJ 287 and Small Mass Ratio Supermassive Black Hole Binary Candidates
The first ever global simulation of OJ-287 where a companion black hole collides with the disk of the central black hole.
sean-ressler