Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Integrable Scalar Cosmologies I. Foundations and links with String
  Theory   We build a number of integrable one--scalar spatially flat cosmologies, which
play a natural role in inflationary scenarios, examine their behavior in
several cases and draw from them some general lessons on this type of systems,
whose potentials involve combinations of exponential functions, and on similar
non--integrable ones. These include the need for the scalar to emerge from the
initial singularity while climbing up sufficiently steep exponential potentials
("climbing phenomenon") and the inevitable collapse in a big Crunch whenever
the scalar tries to settle at negative extrema of the potential. We also
elaborate on the links between these types of potentials and "brane
supersymmetry breaking", a mechanism that ties together string scale and scale
of supersymmetry breaking in a class of orientifold models. We show that, under
some assumptions that are spelled out in the text, the extended objects of
these vacua can inject inflationary phases with discrete values of the spectral
index that are determined by the number of unwrapped dimensions of the branes
and by the inverse power with which the string coupling $g_s$ enters their
world--volume actions. An NS fivebrane, which is interestingly unstable in this
class of models, when wrapped on a small internal cycle would yield a spectral
index that is amusingly close to the experimentally favored PLANCK value ns ~
0.96.

20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn