Many-body physics and black hole physics

During the May, I have been preparing for an application of a research funding called Research Fellowship for Young Scientists (特別研究員), provided by Japan Society for the Promotion of Science (日本学術振興会). Iino-kun in our group suggested that I should write a big and ambitious proposal. I looked up on the internet and found the connection between many-body physics and black hole physics very interesting.

Why do I get interested

In high school, when learning the wave nature of the light, I got to know a thing called holography in the side notes of the textbook. It is a technology that makes it possible to encode all the position information of three-dimentional object into a two-dimentional film. Sounds pretty cool, doesn’t it? This means when you reconstruct the image using the film, the picture you see is 3D, so you can look at it from different directions.

There was a side bonus of this exciting. When I looked up “holography” in the Google, I saw a related physics concept called holographic principle, and a related physicist, Leonard Susskind. At that time, I had heard about String Theory and M-Theory in Steven Hawking’s popular books, A Brief History of Time and The Universe in a Nutshell, and knew they are the deepest possible theories nowadays. This got me even more interested in the word holography.

Many-body physics and holographic principle

When I learn more and more physics, the word AdS/CFT appears a lot, and it is closed related to the holographic principle. Back in 2018, when looking for potential supervisors, I notice the following picture in the perimeter institute,

AdS/CFT pattern

where they claim something called tensor network somehow can give rise to the AdS/CFT correspondence. The picture must affect me a lot implicitly so that I end up working in my current group. As it turns out, the more precise meaning of this picture is saying that the wave function of a one-dimensional quantum lattice system at criticality, which is related to a conformal field theory (CFT), has an entanglement structure looks like an anti-de Sitter (AdS) space. Of the criticality, the wave function will terminate middle radially, and is in some sense related to black holes, as is explained in this review article, Quantum many-body physics from a gravitational lens.

As a result, I wrote this interesting connection between many-body physics and gravitational physics in my research proposal. Maybe someday in the future we can simulate a black hole in a small piece of strangle metal in the laboratory.

Xinliang (Bruce) Lyu

Working on my way to become a theoretical physicist!

This Post Has 4 Comments

  1. Steve

    Hello,

    I’m so inspired with you work, especially because you managed to change fields and it really resonate with me as I’m a civil engineer and I found myself really not enjoying it at all. I want to change my studies to study earth atmosphere and dynamics of the climate change and I’m currently inspired by you and want to focus more of the study of climate topics and fluid dynamics to reach my goal.

    Thank you so much for the Blog and keep it going.
    Steve

    1. I’m very happy that my experience inspires you!

      Good luck with your study and future career!

      Bruce

  2. Ene

    Hello Xinliang,

    I stumbled on a post of yours in Scott’s blog. I have a question about your ultra learning project. How did you keep up with such a high amount of learning while doing graduate school?

    How hard was it to handle both curricula? How deep did you plan for it? And how were you able to reach out to a professor?

    I’m working on an ultra learning project in Neuroscience and this could help me tremendously.

    1. Xinliang (Bruce) Lyu

      Hi Ene,

      I have a post discussing all the details about my physics self-study project. See the second paragraph of the About page and the link there.
      The key is to have a rough plan about what you are going to learn during a specific period of time, say, a semester or half a year. It is also useful to keep a time log, tracking how much time you spend on your self- study project, so you can adjust accordingly.

      For master’s course in China, there is spare time for self study, because the course is in principle designed for students who plan to go to industries, instead of academia, so most of the students spend much time doing internship and preparing for their job during the master’s course. I basically spent those time doing my self-study project, and my rough goal at that time is to spend about 4 hours a day, 4 to 6 days a week on the self-study project.

      I got to know a Georgetown professor in a quantum mechanics course in edX by accident. I found my current professor by browsing the websites of my dream schools and looking for the things I found interesting. The letter of recommendation from the Georgetown professor played an important role in my admission, I believe.

      Good luck with your learning project in Neuroscience!

      Best,
      Bruce

Leave a Reply