## Holographic Duality with Random Tensor Network

**Journal Club Presentations**

- This is a talk among a series of talk given in the high energy journal club intended to understand the black hole information problem better
- (2021) Ryu-Takayanagi, Lewkowycz-Maldacena, Faulkner-Lewkowycz-Maldacena, and Quantum Extremal Surfaces (RT/LM/FLM/QES/BBQ)

- This is basic intro to CFT, followed by other talks in the high energy journal club leading into more important concepts and models in 2D CFT
- (2021) What the heck is CFT, Part I

- This is an overview of recent breakthroughs in black hole info paradox, in undergrad friendly languages
- This is a talk extended from my term paper on entropy and computational power of universe

## Term Papers

- In this term paper, I explained the path integral derivation for the Ryu-Takayanagi formula with gravity in a box set up.
- (2021) Paper

- My term project on the canonical formulation of general relativity for a class on quantum gravity path integral, baby universes, and black hole information problem. My note for this class can be found here [to be uploaded].
- (2021) Presentation slides
- (2021) Paper

- I wrote this short paper on black hole accretion disk for the fluid dynamics class
- Here is one review I wrote to explain motivation and the origin of this cute little idea of "entropy", which turns out to carry profound connections to how we understand information and physics. Then I draw connection to black hole thermodynamics, starting with the generalized second law and Bekenstein bound. Finally I explain how the black hole can be the ultimate quantum computer, and apply the same reasoning to calculate the computational power of our universe.
- Here is one for the group theory class

## Past Research Interests

**Magnetic Field Insensitive Radio-Frequency Dressed Qubits**

[Descriptions to be added]

**Temperatures of the Galilean Satellites**

[Descriptions to be added]

**Orbit Determination for Near-Earth Asteroid**

Near-Earth Asteroids (NEA) impose a great threat to Earth due to their destructive impact upon collision, so it is crucial that we study and understand their orbits to appropriately analyze their probability of collision in any foreseeable future. In this research, together with Elisa Zhao and Hernan Valles, under supervision of Dr. Cassandra Fallscheer and Dr. Michael Dubson, we used direct imaging to obtain a series of data across a month, and numerically implemented Gauss's method to compute a preliminary orbit of the asteroid, and then use the least squares methods to obtain corrections and solve iteratively. Our results showed slight updates compared to previous calculation. The results were sent to the Minor Planet Center and were accepted.

Besides the Gauss's method, which utilizes topocentric coordinates, there is also the Laplace's method, which utilizes the geocentric coordinate. Both are good in calculating the preliminary orbit. One good review for such method can be found in this note.

**Trajectory Optimization for Laser-Propelled Spacecraft**

In the DE-STAR lab, we propose to use phased laser array in Low-Earth Orbit(LEO) to apply on the spacecraft for higher speed during the interstellar travel. In our simulation, The idea is to first have both the spacecraft and the laser in the LEO and we turn the laser on and off towards the spacecraft. Sometimes when laser and spacecraft are opposing each other, the laser must be turned off to avoid backfiring. In the end, we realized that energy transfer from the laser to spacecraft is the most efficient when spacecraft and laser reconvene (i.e. meet at the perigee of the spacecraft orbit) as many time as possible before the spacecraft escapes the Earth. So at every close encounter, we integrate forward to maximize the number of future reconvene in response to the amount of time that we left our laser on.

Originally, when we choose to put the initial position of the spacecraft at different point in the LEO, and count the total amount of time for the spacecraft to reach a certain distance from Earth, we would obtain a random behavior. As the initial position, or other parameters such as laser power, differ only slightly, the total time during transit can shoot up and down without clear pattern. After we optimize the algorithm, allowing maximum efficiency in energy transfer, we also manage to stabilize the this random behavior and the time in transit in general follows a downward trend as the laser power goes up. And overall, we reduced the time in transit for the craft to reach a target in space.

Originally, when we choose to put the initial position of the spacecraft at different point in the LEO, and count the total amount of time for the spacecraft to reach a certain distance from Earth, we would obtain a random behavior. As the initial position, or other parameters such as laser power, differ only slightly, the total time during transit can shoot up and down without clear pattern. After we optimize the algorithm, allowing maximum efficiency in energy transfer, we also manage to stabilize the this random behavior and the time in transit in general follows a downward trend as the laser power goes up. And overall, we reduced the time in transit for the craft to reach a target in space.