So That Was the Answer

"How do you intend to prove that the limit exists as the lattice spacing approaches zero?"

Professor Brian frowned the moment he heard the question.

Did that even need asking?

Of course, you would...

But just then, the answer caught in his throat.

Brian opened his mouth, yet for a long moment, not a single word came out.

How do you prove that the limit exists as the lattice spacing approaches zero?

Fuck... how was he supposed to prove that?

When he wrote his twenty-page paper, he had apparently taken it as a given. He could hardly blame himself. It was such a minor detail that it scarcely seemed worth discussing at length in the paper.

A bead of cold sweat slid down his forehead.

"That's a very interesting question... Yes, very interesting. Of course I can prove it..." Brian muttered to buy time. Sweat poured down his face as his mind raced for a way to solve the problem.

Unfortunately, the more anxious he grew, the slower his thoughts became.

The lecture hall fell silent.

The silence was terrifying.

Stalling, it turned out, was no help at all.

As Professor Brian stood there, unable to answer, the once-quiet audience began to stir.

Witten gave his student one last surprised look, then closed the notebook spread across his knees. "Looks like we can forget about that invitation to review for Mathematical Physics," he said with a smile.

The gauge-invariant action in Toroidal Euclidean Spacetime.

It was an obscure and particularly tricky angle.

Had he been reviewing the paper, he might not have missed a detail like that. But finding such an elusive flaw during a presentation was difficult when there were so many questions worth considering.

Then he remembered that Luo Wenxuan now worked at the Jinling Institute for Advanced