Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cosmological Inflation and the Nature of Time   Recent advances in observational cosmology are changing the way we view the
nature of time. In general relativity, the freedom in choosing a time
hypersurface has hampered the implementation of the theory. Fortunately,
Hamilton-Jacobi theory enables one to describe all time hypersurfaces on an
equal footing. Using an expansion in powers of the spatial curvature, one may
solve for the wavefunctional in a semiclassical approximation. In this way, one
may readily compare predictions of various inflation models with observations
of microwave background anisotropies and galaxy clustering.

27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics