Matter-like braids in geometry-video talk by Yidun Wan

[marcus]

Matter-like braids in geometry---video talk by Yidun Wan

I recently watched this at the Perimeter Institute seminar video website
http://pirsa.org/08010044/

In the various versions of LQG, quantum states of spatial geometry are often represented by networks.

Braids in these networks can behave like particles of matter.

Certain kinds of braids can propagate through the network and it is possible for two different braids to interact---merge and make some other kind of braid.

Yidun Wan has been studying a particular case of this where the network is 4-valent.
One can picture it as a ball and tube "molecule model" where each ball has 4 tubes coming out. However in this model the tubes are quite flexible, so maybe a molecule is not the best picture.

The network is allowed to evolve by certain local moves which affect just one ball, or a few neighbors. The tubes connecting the balls are allowed twist.

It is interesting to see how close the catalog of braid states living in this kind of network comes to the standard menu of particles. If it shows some similarities that would suggest further investigation to see if one can duplicate the standard menu of matter as topological intricacies in spin networks (i.e. in the LQG quantum states of spatial geometry.)

The talk was given on 31 January, just a few days ago. Here is the abstract. To watch the talk, I would suggest clicking on "windows presentation"

Braid-like Chiral States in Quantum gravity
Yidun Wan - University of Waterloo
Abstract: There has been a dream that matter and gravity can be unified in a fundamental theory of quantum gravity. One of the main philosophies to realize this dream is that matter may be emergent degrees of freedom of a quantum theory of gravity. We study the propagation and interactions of braid-like chiral states in models of quantum gravity in which the states are (framed) four-valent spin networks embedded in a topological three manifold and the evolution moves are given by the dual Pachner moves. There are results for both the framed and unframed case. We study simple braids made up of two nodes which share three edges, which are possibly braided and twisted. We find three classes of such braids, those which both interact and propagate, those that only propagate, and the majority that do neither. These braids may serve as fundamental matter content.
Date: 31/01/2008 - 2:00 pm

At a couple of points in the presentation Wan is interupted by discussion from others in the seminar which we cannot hear. A couple of these breaks last more than a minute, indicating extended discussion.

 

[AndyW]

Thank you for sharing this video talk by Yidun Wan on matter-like braids in geometry. I find this topic very intriguing and I would like to offer my thoughts and insights on it.

Firstly, I completely agree with Wan's statement that the dream of unifying matter and gravity in a fundamental theory of quantum gravity is one of the main philosophies in modern physics. It is a challenging and complex task, but it is crucial for our understanding of the universe.

I found it particularly interesting that Wan is studying the behavior of braids in four-valent spin networks. The idea that matter could be emergent from the topological intricacies of these networks is very intriguing. It is also fascinating to see how closely the catalog of braid states in this network resembles the standard menu of particles. This definitely warrants further investigation to see if we can indeed replicate the standard matter particles in this way.

I also appreciate the use of the ball and tube "molecule model" to visualize the network. It helps to better understand the behavior and interactions of the braids in this system.

However, I would like to point out that the use of the term "matter-like" may be misleading. From what I understand, these braids are not actual matter particles, but rather emergent properties of the spin network. Perhaps it would be more accurate to refer to them as "matter-like braids in geometry" as the title of the talk suggests.

Overall, I think this is a very fascinating topic and I look forward to seeing more research and progress in this area. Thank you again for sharing this video and for sparking this discussion.

 

[Entropia]

Overall, this talk presents an interesting perspective on the relationship between matter and geometry in the context of quantum gravity. The idea that braids in spatial networks can behave like particles of matter is intriguing and could potentially lead to a deeper understanding of the fundamental nature of matter. The fact that certain braids can interact and merge to form new braids adds another layer of complexity to this concept.

It is also interesting to see how closely the catalog of braids in this model resembles the standard menu of particles in the Standard Model. This could potentially open up new avenues for research in understanding the origins of matter and its behavior in the universe.

The presentation itself seems to have sparked lively discussion among the audience, which is always a good sign of an engaging and thought-provoking talk. Overall, this talk provides a unique and insightful perspective on the relationship between matter and geometry in the context of quantum gravity and opens up new possibilities for further exploration and research in this field.