Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Initial state effects on the cosmic microwave background and
  trans-planckian physics   There exist a one complex parameter family of de Sitter invariant vacua,
known as alpha vacua. In the context of slow roll inflation, we show that all
but the Bunch-Davies vacuum generates unacceptable production of high energy
particles at the end of inflation. As a simple model for the effects of
trans-planckian physics, we go on to consider non-de Sitter invariant vacua
obtained by patching modes in the Bunch-Davies vacuum above some momentum scale
M_c, with modes in an alpha vacuum below M_c. Choosing M_c near the Planck
scale M_pl, we find acceptable levels of hard particle production, and
corrections to the cosmic microwave perturbations at the level of H M_pl/M_c^2,
where H is the Hubble parameter during inflation. More general initial states
of this type with H<< M_c << M_pl can give corrections to the spectrum of
cosmic microwave background perturbations at order 1. The parameter
characterizing the alpha-vacuum during inflation is a new cosmological
observable.

14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math