Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Higher-spin massless S-matrices in four-dimensions   On-shell, analytic S-matrix elements in massless theories are constructed
from a finite set of primitive three-point amplitudes, which are fixed by
Poincare invariance up to an overall numerical constant. We classify \emph{all}
such three-point amplitudes in four-dimensions. Imposing the simplest
incarnation of Locality and Unitarity on four-particle amplitudes constructed
from these three-particle amplitudes rules out all but an extremely small
subset of interactions among higher-spin massless states. Notably, the
equivalence principle, and the Weinberg-Witten theorem, are simple corollaries
of this principle. Further, no massless states with helicity larger than two
may consistently interact with massless gravitons. Chromodynamics,
electrodynamics, Yukawa and $\phi^3$-theories are the only marginal and
relevant interactions between massless states. Finally, we show that
supersymmetry naturally emerges as a consistency condition on four-particle
amplitudes involving spin-3/2 states, which must always interact
gravitationally.

26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess