Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectral Parameters for Scattering Amplitudes in N=4 Super Yang-Mills
  Theory   Planar N=4 Super Yang-Mills theory appears to be a quantum integrable
four-dimensional conformal theory. This has been used to find equations
believed to describe its exact spectrum of anomalous dimensions. Integrability
seemingly also extends to the planar space-time scattering amplitudes of the
N=4 model, which show strong signs of Yangian invariance. However, in
contradistinction to the spectral problem, this has not yet led to equations
determining the exact amplitudes. We propose that the missing element is the
spectral parameter, ubiquitous in integrable models. We show that it may indeed
be included into recent on-shell approaches to scattering amplitude integrands,
providing a natural deformation of the latter. Under some constraints, Yangian
symmetry is preserved. Finally we speculate that the spectral parameter might
also be the regulator of choice for controlling the infrared divergences
appearing when integrating the integrands in exactly four dimensions.

11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th