Spontaneous Decay of the Effective Cosmological Constant
نویسنده
چکیده
We discuss the notion that quantum fields may induce an effective time dependent cosmological constant which decays from a large initial value. It is shown that such cosmological models are viable in a non de Sitter spacetime.
منابع مشابه
Decaying cosmological parameter in the early universe from NKK theory of gravity
Cosmological observations imply that there exists an extremely small upper limit on the vacuum energy density in the present state of our universe. This stands in sharp contradiction with theoretical predictions [1]. In fact, any mass scale in particle physics contributes to the vacuum energy density much larger than this upper bound [2]. According to modern quantum field theory, the structure ...
متن کاملUniverse Decay, Inflation and the Large Eigenvalue of the Cosmological Constant Seesaw
We discuss implications of the large eigenvalue of the cosmological constant seesaw mechanism extending hep-th/0602112 and hep-th/0604108. While the previous papers focused on the small eigenvalue as a cosmological constant associated with the accelerating Universe, here we draw attention to the physical implications of the large eigenvalue. In particular we find that the large eigenvalue can g...
متن کاملBulk Viscous Bianchi Type VI0 Cosmological Model in the Self-creation Theory of Gravitation and in the General Theory of Relativity
In the second self-creation theory of gravitation and in the general theory of relativity, Bianchi type VI0 cosmological model in the presence of viscous fluid is studied. An exact solution of the field equations is given by considering the cosmological model yields a constant decelerations parameter q=constant and the coefficients of the metric are taken as A(t)=[c1t+c<su...
متن کاملOn the Possibility of Large Axion Decay Constants
The decay constant of the QCD axion is required by observation to be small compared to the Planck scale. In theories of “natural inflation,” and certain proposed anthropic solutions of the cosmological constant problem, it would be interesting to obtain a large decay constant for axion-like fields from microscopic physics. String theory is the only context in which one can sensibly address this...
متن کاملSpacetimes admitting quasi-conformal curvature tensor
The object of the present paper is to study spacetimes admitting quasi-conformal curvature tensor. At first we prove that a quasi-conformally flat spacetime is Einstein and hence it is of constant curvature and the energy momentum tensor of such a spacetime satisfying Einstein's field equation with cosmological constant is covariant constant. Next, we prove that if the perfect flui...
متن کامل