All Questions
6
questions
1
vote
1
answer
146
views
How did the two copies of the Witt algebra become two copies of the Virasoro algebra in the CFT?
The Virasoro algebra
\begin{equation}
[L_m,L_n]=(m-n) L_{m+n} +\frac{c}{12} (m^3-m) \delta_{m+n,0}
\end{equation}
of the stress energy tensor $T$ was said to follow from the witt algebra of the local ...
- 3,256
5
votes
2
answers
759
views
Inconsistency in the normal ordered Virasoro algebra
I seem to have found a basic contradiction when it comes to the commutation relations of the Virasoro algebra with normal ordered operators and I am not sure what the resolution is.
If we have a ...
- 11.6k
0
votes
1
answer
116
views
Proposal of the Virasoro modes and algebra
Hi I am wondering what the first published paper on Virasoro modes was? And what about Virasoro algebra?
- 93
1
vote
1
answer
137
views
How to derive an $E_8$ algebra?
What is the simplest way to derive an $E_8$ algebra? I am not interested in $E_8$ itself but what would compel one to think about it. I know for example why you would want to think about $SU(2)$ and ...
user151266
10
votes
1
answer
671
views
Confusion about two definitions of anomalies
As I am currently studying for an exam about quantum field theory and string theory, I got confused about the notion of "anomalies" and how they are actually defined. Similar questions have already ...
- 7,309
5
votes
1
answer
382
views
Why Must Conserved Currents of Lorentz Symmetry Satisfy the Lorentz Algebra?
I've seen it written many times that the commutation relation
$$[M^{I-},M^{J-}]=0$$
is required for Lorentz invariance in the light cone gauge quantisation of the bosonic string. This follows ...
- 7,936