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7 questions with no upvoted or accepted answers
2 votes
0 answers
115 views

What is the definition of bound state in quantum field theory?

I asked a question a while a go what is a bound state and the question was closed because there is a similar question. Now since best description we have to describe nature in quantum field theory How ...
amilton moreira's user avatar
2 votes
1 answer
87 views

What is a neutrino state if not a particle?

When reading about the 2015 Nobel prize and how this led to the possibility of the existence of sterile neutrinos I am told that: "(...) three active neutrinos $\nu_e$, $\nu_\mu$, $\nu_\tau$, are ...
user7077252's user avatar
0 votes
0 answers
74 views

What is a state space in quantum mechanics?

I have begun reading chapter 11 of Zwiebach's "A First Course in String Theory" 2nd edition. Section 11.2 deals with the Heisenberg and Schrodinger pictures. Both pictures will use the same &...
cows's user avatar
  • 246
0 votes
0 answers
54 views

Inner product evaluation in QM

On wikipedia on the page for inner product it states that for any two $x,y$ in a vector space $V$ the inner product $(\cdot , \cdot)$ satisfies $(ax, y) = a(x,y)$ where $a\in\mathbb{C}$. The inner ...
Chan's user avatar
  • 73
0 votes
0 answers
154 views

Off-shell vs half off-shell vs fully off-shell $T$-matrix

I know what are on-shell particles, but I want to know what are off-shell, and half off-shell, and fully off-shell states? and how we decide to consider one of these states in evaluating $T$-Matrix?
tahami's user avatar
  • 11
0 votes
0 answers
418 views

Difference between pure and thermal states

As far as I know by inserting a harmonic potential $V(x) = \frac{1}{2}m \omega x^2$ into the time-independent schrödinger equation I can obtain the wave-functions eigenstates and eigenvalues (energies)...
CatoMaths's user avatar
  • 415
-2 votes
1 answer
89 views

What is meant by Projected Hilbert space?

What is meant by Projected Hilbert space? I know almost everything about coherent states. But I don't know the use of projected coherent states. I googled, but I can't find any source.
Reya Rose's user avatar