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Did the Big Bang happen at a point?

Why do we not have spin greater than 2?

From where (in space-time) does Hawking radiation originate?

What does it mean for a Hamiltonian or system to be gapped or gapless?

Are vacuum fluctuations really happening all the time?

How does Fermat's principle make light choose a straight path over a short path?

Interval preserving transformations are linear in special relativity

Basic questions in Majorana fermions

Is there a way to split a black hole?

Differences between symmetric, Hermitian, self-adjoint, and essentially self-adjoint operators

What is the analog of the Aharonov-Bohm effect for general gauge fields and for gravity?

When one discusses the "boundary" of Anti-de Sitter space, what do they mean precisely?

Virtual particles and physical laws

How did we know that the Dirac equation describes the electron but not the proton?

Gelfand-Yaglom theorem for functional determinants

How does QFT help with entanglement?

What is "Dynamical phase transition"?

Is the harmonic oscillator potential unique in having equally spaced discrete energy levels?

What is so topological about topological phase transitions?

Why does the Coarse-grained Entropy increase?

Is ground state and vacuum state the same thing?

Counting degrees of freedom for gravitational waves as a gauge field

Counting Degrees of Freedom in Field Theories

What do physicists mean by an "integrable system"?

Why should there be one-particle states in an interacting quantum field theory?

Homogeneity of space implies linearity of Lorentz transformations

How do I define time-ordering for Wightman functions?

What is the general procedure for constructing the Penrose diagram for an arbitrary $(1+1)d$ spacetime?

't Hooft vs ABJ anomalies [closed]

How can a find the symmetry group of a Lagrangian?