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6 votes
0 answers
300 views

What intuition led to J. Wang and X.G. Wen's lattice formulation of the 3450 chiral gauge theory?

In the paper cited below, Juven Wang and Xiao-Gang Wen give an example of a lattice model that reduces to a chiral $U(1)$ gauge theory at low energy. The low energy theory is called the $3450$ model. ...
7 votes
1 answer
379 views

On-site symmetries can be gauged, but is a gaugeable symmetry necessarily on-site?

I've always liked lattice QFT because it's mathematically unambiguous and non-perturbative, but it does have two drawbacks: (1) the lattice is artificial, and (2) some features are messy. One of those ...
5 votes
1 answer
218 views

Phenomenology application of quantum anomaly

Anomaly means that: the system has a symmetry at classical level (both discrete and continous), but when we quantize the theory, the system no longer holds the symmetry. I'm wondering for every ...
7 votes
2 answers
2k views

Anomaly inflow mechanism

I know very simple example of anomaly inflow. See section 4.4 in David Tong: Lectures on Gauge Theory. As I read, such mechanism have some applications in condensed matter and in quantum field theory, ...
3 votes
1 answer
284 views

Anomalies on boundary and bulk physics

Few times I faced with such statements: The gravitational anomaly of the 1+1d boundary system is known to be proportional to the thermal Hall conductivity of the 2+1 dimensional bulk How ...
0 votes
0 answers
118 views

A Universe with only a single fermion

Is a Universe with only a single fermion anomalous instead of free from anomalies? (e.g. electron, defined through fermi statistics with exchange statistics with a gained $-1$ sign, or rotating 360 ...
8 votes
1 answer
1k views

Zumino's consistent and covariant anomalies - applied to quantum hall?

What is the `physical' meaning of consistent anomalies and covariant anomalies? Perhaps a good Reference is: Consistent and covariant anomalies in gauge and gravitational theories - William A. ...
4 votes
0 answers
516 views

Anomaly for Majorana fermion?

In 4-spacetime dimension, is there U(1) gauge field chiral anomaly associated with Majorana fermion (or I am not sure if it is equivalent, majorana representation)? Besides, I have read from several ...
6 votes
0 answers
866 views

Descent equation and anomaly polynomial [closed]

I am just reading Ryu, Moore and Ludwig's paper on classifications of topological insulators and quantum anomaly. They are trying to relate the quantum anomaly as a signal of the presence of a ...