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3 votes

What does the $N$ in $SU(N)$ mean?

There's a few things going on here. Global vs Gauge Symmetries First, it's true that $SU(2) \sim SO(3)$ if you only worry about small rotations. The more precise statement is that $SU(2)$ is the "...
11zaq's user avatar
  • 871
2 votes

What does the $N$ in $SU(N)$ mean?

$N$ denotes the dimension of the so-called defining representation. The group SU(N) is the group of $N\times N$ special unitary matrices (i.e. determinant=1). Similarly, the group $U(N)$ is the group ...
ZeroTheHero's user avatar
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2 votes

Non-abelian Yang-Mills in 1+1 dimensions

Let us choose the axial gauge $$A_1~=~0.\tag{A}$$ Then the chromo-electric field is $$F_{10}~=~\partial_1A_0-\partial_0A_1+[A_1,A_0]~\stackrel{(A)}{=}~\partial_1A_0.\tag{B}$$ NB: Be aware that $F_{10}...
Qmechanic's user avatar
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1 vote

What does the $N$ in $SU(N)$ mean?

$SU(N)$ is a mathematical object (a group), and the $N$ means different things in different contexts. Asking what the $N$ means is a bit like asking what the variable $x$ means in $x^2 + x + 1$; it ...
QCD_IS_GOOD's user avatar
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1 vote

Is the factorization method of Hamiltonian related to the theory of Lie groups?

In this case it is not symmetry (described by Lie groups) but supersymmetry that accounts for the explicit solvability. Indeed, the factorization method of Infeld an Hull is closely related to ...
Arnold Neumaier's user avatar

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