3
votes
1answer
91 views

No Lagrangian description v.s. No quasi-particle description

This post is aimed to stimulate some discussions. We are familiar with many physical descriptions and theories of the (many-body quantum) system, with both quasi-particle description and Lagrangian ...
3
votes
0answers
70 views

Is there a critical order of the Abelian gauge theory in (2+1)D

In (2+1)D spacetime, it is known that the $U(1)$ gauge theory is always confined (according to Polyakov), while the $\mathbb{Z}_2$ gauge theory can support a deconfined phase. Now consider a generic ...
12
votes
1answer
437 views

What are some predictions from string theory that say some crystalline materials “will end up in one of many lowest-energy ground states?”

I am referring to this recent "news feature" by Zeeya Merali from Nature magazine www.nature.com/uidfinder/10.1038/478302a. Here is the specific quote: "To make matters worse, some of the testable ...
5
votes
2answers
692 views

How much can AdS/CMT tell us?

I will begin my research on AdS/CMT, however I find AdS/CMT is only a phenomelogical method, so I want to know can AdS/CMT give some results the condensed matter physicists can not give, or even ...