Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Back reaction of the neutrino field in an Einstein universe   The back reaction effect of the neutrino field at finite temperature in the
background of the static Einstein universe is investigated. A relationship
between the temperature of the universe and its radius is found. As in the
previously studied cases of the massless scalar field and the photon field,
this relation exhibit a minimum radius below which no self-consistent solution
for the Einstein field equation can be found. A maximum temperature marks the
transition from a vacuum dominated state to the radiation dominated state
universe. In the light of the results obtained for the scalar, neutrino and
photon fields the role of the back reaction of quantum fields in controling the
value of the cosmological constant is briefly discussed.

25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
1
The categories of this paper are: cs
19
The categories of this paper are: eess