Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The role of CMB spectral distortions in the Hubble tension: a proof of
  principle   Although both early and late-time modifications of the $\Lambda$CDM model
have been proposed to address the Hubble tension, compelling arguments suggest
that for a solution to be successful it needs to modify the expansion history
of the universe prior to recombination. This greatly increases the importance
of precise CMB observations, and in this letter we make the argument for CMB
spectral distortions, highlighting their potential role in constraining models
that introduce significant shifts in the standard $\Lambda$CDM parameters, such
as the scalar spectral index, in attempt to solve the Hubble tension.

30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg