Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Variation of fundamental parameters and dark energy. A principal
  component approach   We discuss methods based on Principal Component Analysis to constrain the
dark energy equation of state using a combination of Type Ia supernovae at low
redshift and spectroscopic measurements of varying fundamental couplings at
higher redshifts. We discuss the performance of this method when future
better-quality datasets are available, focusing on two forthcoming ESO
spectrographs - ESPRESSO for the VLT and CODEX for the E-ELT - which include
these measurements as a key part of their science cases. These can realize the
prospect of a detailed characterization of dark energy properties almost all
the way up to redshift 4.

29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom