Possible solution to the cosmologicalconstant problem
Abstract
Classically, the unimodular theory of gravity with a constrained determinant g_{μν} is equivalent to general relativity augmented by an arbitrary cosmological constant Λ, which arises as an integration constant. At the quantum level we argue that an integration over Λ should be included in the Euclidean path integral for the vacuum functional. The fully renormalized Λ=0 overwhelmingly dominates all other contributions yielding a zero observed cosmological constant. While the technical part of our argument is similar to that of the ``wormhole'' argument, the two approaches are logically different.
 Publication:

Physical Review Letters
 Pub Date:
 October 1990
 DOI:
 10.1103/PhysRevLett.65.1972
 Bibcode:
 1990PhRvL..65.1972N
 Keywords:

 Cosmology;
 Gravitation Theory;
 Relativistic Theory;
 Singularity (Mathematics);
 Space Sciences (General);
 04.60.+n;
 04.20.Cv;
 04.50.+h;
 98.80.Dr;
 Fundamental problems and general formalism;
 Gravity in more than four dimensions KaluzaKlein theory unified field theories;
 alternative theories of gravity