Questions tagged [higher-spin]
A theory of interacting fields of arbitrary spin. Generalizes Yang-Mills as a theory of spin-one, gravity as a theory of spin-two to fields of any spin.
59 questions
1 vote
0 answers
94 views
Why are fundamental particle spins so small? [duplicate]
So by my understanding, all the particles known to exist are either spin 1, 1/2 or 0. While I don't follow the details, I've also heard the spin-statistics theorem's conclusion that in 3+1D spacetime, ...
- 1,094
4 votes
0 answers
89 views
Twisted Operators
In higher-spin CFT, operators organize themselves into additive multi-twist. I am a bit confused as to the use of "twist-two", "leading-twist", etc. Especially when it mentioned in ...
1 vote
0 answers
59 views
Gauge Invariance and Degrees of Freedom [duplicate]
According to Wigner's classification, any massless particle (except for scalars) has 2 degrees of freedom i 4D. This reduction is usually understood in terms of gauge invariance. For instance, a ...
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2 votes
1 answer
178 views
Higher massive integer spin field (or spin-3 field)
I've been revisiting chapter 8 of Schwartz's Quantum Field Theory book. Toward the end, he describes a method for constructing the Lagrangian of massive integer spin particles by separating the ...
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1 vote
1 answer
149 views
Geometrical interpretation of gauge fields of spin other than 2
Gravitation can be interpreted as a gauge theory with a spin 2 graviton field. This graviton field in general relativity is also interpreter as a Riemannian metric. Do other gauge theories also have ...
1 vote
1 answer
149 views
Counting of degrees of freedom in Higher Spin Theories in curved spacetime
In 4d Minkowski, a (bosonic) tensor field with spin $s\in\mathbb{N}_+$ are constrained by Poincaré symmetry, and the physical degrees of freedom can be counted by considering the little group: a spin-$...
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0 votes
1 answer
164 views
Is there an equivalent to the Klein-Gordon and Dirac Equations for Vector and other fields?
The Klein-Gordon equation describes a scalar field, and the Dirac Equation describes a spinor field. Is there an equivalent equation for a vector field? As well as spin 3/2 and spin 2 tensor fields? ...
1 vote
1 answer
167 views
Mathematical description of higher spin gauge theories
Ordinary Yang-Mills gauge theory giving spin 1 gauge bosons can be mathematically described by connection 1-forms and curvature of principal bundles. I wonder, what the proper mathematical description ...
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1 vote
0 answers
71 views
Rarita-Schwinger Equation in solids?
Can this equation, at least in its non-relativistic limit "if it exist" in 3 dimensional, model holes in the valence band for Zinc blende semiconductor materials for example, since in three ...
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9 votes
1 answer
322 views
Free higher spin fields and gravity
There are soft theorems that suggest that any massless boson with spin higher than 2 should be a free field theory and cannot have interactions. Does this mean that one cannot embed such fields into a ...
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0 votes
0 answers
127 views
Spin 3/2 field in higher dimensions
The Lagrangian and equation of spin 3/2 field in a general dimension D is given on page 96 of Supergravity ( textbook by Freedman and Proeyen, 2012 ). The action is : $$ S = - \int d^Dx \bar{\psi}_{\...
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2 votes
1 answer
170 views
How should we imbed massive spin-3 in a Lorentz covariant tensor? (degree of freedom-wise)
I'm not asking for Weinberg's systematic approach. Rather, I'm more concerned with how to get the correct degrees of freedom(dof) slickly for the moment. I believe it should be imbedded in the rank 3 ...
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0 votes
2 answers
235 views
Orthonormal basis of higher-spin operators
For a spin-1/2 degree of freedom, we all know the Hilbert space of states is two-dimensional. The space of linear operators on that Hilbert space has dimension $2^{2}=4$, a basis of which is $S_{x},S_{...
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2 votes
0 answers
57 views
No-go theorem evasion for higher spin (super)string theory
The inclusion of (conventional) SUSY truncates spin states in (super)string theory and M-theory. My question here is the following: could a non-standard SUSY algebra be constructed in such a way (...
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2 votes
0 answers
55 views
Well-posed classical field equations for spin $s>1$ fields
Wald Section $13.2$ states that the initial value formulation of the minimally coupled Dirac equation on curved spacetime is not well posed for spin $s>1$ spinor fields. However, it does not state ...
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