Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Horizon-preserving dualities and perturbations in non-canonical scalar
  field cosmologies   We generalize the cosmological duality between inflation and cyclic
contraction under the interchange $a \leftrightarrow H$ to the case of
non-canonical scalar field theories with varying speed of sound. The single
duality in the canonical case generalizes to a family of three dualities
constructed to leave the cosmological acoustic horizon invariant. We find three
classes of models: (I) DBI inflation, (II) the non-canonical generalization of
cyclic contraction, and (III) a new cosmological solution with rapidly
decreasing speed of sound and relatively slowly growing scale factor, which we
dub {\it stalled} cosmology. We construct dual analogs to the inflationary slow
roll approximation, and solve for the curvature perturbation in all three
cases. Both cyclic contraction and stalled cosmology predict a strongly blue
spectrum for the curvature perturbations inconsistent with observations.

29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess