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
Professional Summary
Xinyu Li is an assistant professor in the Department of Astronomy, Tsinghua University. He is fond of discovering fundamental physical laws from the vast observation of various astrophysical objects. His research areas are high energy astrophysics, plasma astrophysics and cosmology. His research topics cover a broad range of physical scales: from the smallest fundamental particles like electrons and ultralight axions, to neutron stars, black holes and galaxies, and to the largest scale structure of the universe.
Education
PhD Physics
2013-9
2019-9
Columbia University
MS Theoretical Physics
2012-9
2013-6
Perimeter Institute
BS Physics and Mathematics
2008-9
2012-6
University of Hong Kong
Interests
High Energy Astrophysics
Black Holes and Neutron Stars
Cosmology
Plasma Physics
Dark Matter
Machine Learning
Everything interesting
📚 My Research
I am a theoretical physicist, eager to learn about the laws of nature.
I apply various quantitative methods to comprehensively investigate how fundamental physics laws that governs the motion of subatomic particles can shape our universe.
I write code to reproduce the cosmos on huge computer clusters —- a world model not driven by data, but from physics.
I am curious to learn and explore the world beyond my main research area. How to build world model from physics for AI? How patterns merge in complex systems?
Please feel free to contact me if you would like to chat and collaborate 😃
Featured Publications
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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
Force-free Wave Interaction in Magnetar Magnetospheres: Computational Modeling in Axisymmetry
How waves interact in the magnetar magnetosphere?
jens-mahlmann
An Intermediate-field Fast Radio Burst Model and the Quasi-periodic Oscillation
A new theory of Fast Radio Burst.
jie-shuang-wang
Fast Dissipation of Colliding Alfvén Waves in a Magnetically Dominated Plasma
A new channel of fast magnetic energy dissipation.
Recent Publications
Electromagnetic Signatures of Supermassive Binary Black Holes. I. Thermal Synchrotron, Self-Lensing Flares, and Jet Precession.
Journal Name,
2026.
The effects of star-gas interactions on binary evolution in open clusters.
Journal Name,
2026.
Recent & Upcoming Talks
How to observe (spuermassive) black hole binaries?
What can we learn from GRMHD simulations?
Aflven wave dynamics in magnetar magnetosphere and applications to Fast Radio Burst
How Alfven wave dynamics can power Fast Radio Burst?
Cosmology of Fuzzy Dark Matter Model
Numerical study of Fuzzy Dark Matter model.
Blog
Conservation of Topological Quantities in Euler Equation
The fluid equations in the conservative form are $$\begin{aligned} \partial_t \rho +\nabla\cdot(\rho \boldsymbol{u})&=&0 \\ \partial_t (\rho u^i)+\nabla\cdot(\rho …
Eliminating Pressure for Incompressible MHD
In the formulation of Elsasser’s variables $\mathbf{U} = \mathbf{v}+\mathbf{b}$ and $\mathbf{W} = \mathbf{v}-\mathbf{b}$, $$\begin{aligned} &&\partial_t \mathbf{U} = …
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 $F_{\mu\nu}$.
MHD Turbulence Cascade
Consider the ideal incompressible MHD wave governed by the equations $$\begin{aligned} \frac{\partial \vec{v}}{\partial t}+\vec{v}\cdot \nabla\vec{v}&=&\vec{B}\cdot\nabla\vec{B}\\ …
Note on Electrodynamics
Particle Motion in Uniform Perpendicular Electromagnetic Fields A test particle with mass $m$ and charge $q$ moving at velocity $\boldsymbol{v}$ in an electromagnetic field feels …
Relativistic MHD Shock
The energy momentum tensor for a relativistic pressureless fluid is $$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 …