Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hubble constant and dark energy inferred from free-form determined time
  delay distances   Time delays between multiple images of lensed sources can probe the geometry
of the universe. We propose a novel method based on free-form modelling of
gravitational lenses to estimate time-delay distances and, in turn,
cosmological parameters. This approach does not suffer from the degeneracy
between the steepness of the profile and the cosmological parameters. We apply
the method to 18 systems having time delay measurements and find
H_0=69+-6(stat.)+-4(syst.) km s^{-1}Mpc^{-1}. In combination with WMAP9, the
constraints on dark energy are Omega_w=0.68+-0.05 and w=-0.86+-0.17 in a flat
model with constant equation-of-state.

23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph