Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A new approach to the Sachs-Wolfe effect   We present a new approach to the Sachs-Wolfe effect, which is based on the
dynamics of photons in a space and time varying gravitational field. We
consider the influence of plasma dispersion effects on photon propagation, and
establish the limits of validity of the usual results of the standard
cosmological approach, for the large scale temperature anisotropies of the
cosmic microwave background. New dynamical contributions to the integrated
Sachs-Wolfe effect are also discussed.

17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio