Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: What do gravitons say about (unimodular) gravity?   We revisit the problem of constraining the weak field limit of the
gravitational lagrangian from S-matrix properties. From unitarity and Lorentz
invariance of the S-matrix of massless gravitons, we derive on-shell gauge
invariance to consist on the transverse part of the linearised diffeomorphisms
group. Moreover, by looking to the interaction between sources, we conclude
that there exist only two possible lagrangians that lead to a well-defined
covariant interaction, corresponding to the weak field limits of General
Relativity and Unimodular Gravity. Additionally, this result confirms the
equivalence of the S-matrix of both theories around flat space-time.

23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org