Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extended quintessence and the primordial helium abundance   In extended quintessence models, a scalar field which couples to the
curvature scalar R provides most of the energy density of the universe. We
point out that such models can also lead naturally to a decrease in the
primordial abundance of helium-4, relieving the tension which currently exists
between the primordial helium-4 abundance inferred from observations and the
amount predicted by Standard Big Bang Nucleosynthesis (SBBN) corresponding to
the observed deuterium abundance. Using negative power-law potentials for the
quintessence field, we determine the range of model parameters which can lead
to an interesting reduction in the helium-4 abundance, and we show that it
overlaps with the region allowed by other constraints on extended quintessence
models.

3
The categories of this paper are: physics
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ