Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A new relativistic theory for Modified Newtonian Dynamics   We propose a relativistic gravitational theory leading to modified Newtonian
dynamics, a paradigm that explains the observed universal galactic acceleration
scale and related phenomenology. We discuss phenomenological requirements
leading to its construction and demonstrate its agreement with the observed
cosmic microwave background and matter power spectra on linear cosmological
scales. We show that its action expanded to second order is free of ghost
instabilities and discuss its possible embedding in a more fundamental theory.

10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn