New answers tagged

1 vote

Equivalent definition of Hawking quasi-local mass

Specifically, I don't know what the phrase convergence of the outer/inner null normal means. What on earth is this all about? How do I get to know that? Seriously, I don't see how a purely geometrical ...
VaibhavK's user avatar
  • 407
1 vote

Equivalent definition of Hawking quasi-local mass

According to my not so good friend Bard, your question regarding the equivalence of different definitions for the Hawking quasi-local mass highlights an important and subtle topic in general ...
Pato Galmarini's user avatar
2 votes

How do I find the kernel of the shift operator in the solution of 2D Ising model?

To be honest, I'm not sure the $U$ operator exists. The book does not contain its complete consideration. I expect that there may be problems with boundaries and translational invariance. Nevertheless,...
Gec's user avatar
  • 4,900
0 votes

Rigorous underpinnings of infinitesimals in physics

I allow myself to refer to Väth's adorable book Nonstandard Analysis. Nonstandard Analysis works with infinitesimals by extending $\mathbb{R}$ and using a nice tool called "transfer principle&...
user7427029's user avatar
1 vote

Justification of discrete spectrum for $V(x)$ unbounded at $\pm \infty$ in Pauling and Wilson

Yes, there is actually a rigorous proof, for detail's read Simon and Rid, methods of modern mathematical physics, it's the theorem 13.16. (13 roman). It holds for bounded from below hamiltonians (...
0 votes

Implications of unbounded operators in quantum mechanics

I agree with the other answers that the questions boils down on how to define the Born rule and the time evolution without worrying about domains. The time evolution is generated by bounded operators ...
Fiter's user avatar
  • 57
3 votes
Accepted

Physical motivation for the definition of Spin structure

You need the second condition because this $\mathrm{SL}(2,\mathbb{C})$ isn't just a random internal symmetry group (like the gauge groups of Yang-Mills theories, where you indeed just have a $G$-...
ACuriousMind's user avatar
  • 123k
0 votes

Minimal strings and topological strings

In the context of mirror symmetry, the equivalents of the FZZT and ZZ open string partition functions in the B-model correspond to certain A-branes and B-branes, respectively. A-branes in the B-model ...
Don Aborah's user avatar

Top 50 recent answers are included