Cosmological constant in scale-invariant theories
نویسندگان
چکیده
منابع مشابه
Exact cosmological solutions of scale-invariant gravity theories
We have found new anisotropic vacuum solutions for the scale-invariant gravity theories which generalise Einstein’s general relativity to a theory derived from the Lagrangian R. These solutions are expanding universes of Kasner form with an initial spacetime singularity at t = 0 and exist for −1/2 < δ < 1/4 but possess different Kasner index relations to the classic Kasner solution of general r...
متن کاملTheories of the Cosmological Constant
This is a talk given at the conference Critical Dialogues in Cosmology at Princeton University, June 24–27, 1996. It gives a brief summary of our present theoretical understanding regarding the value of the cosmological constant, and describes how to calculate the probability distribution of the observed cosmological constant in cosmological theories with a large number of subuniverses (i. e., ...
متن کاملString Scale Cosmological Constant
The cosmological constant is an unexplained until now phenomena of nature that requires an explanation through string effects. The apparent discrepancy between theory and experiment is enourmous and has already been explained several times by the author including mechanisms. In this work the string theory theory of abolished string modes is documented and given perturbatively to all loop orders...
متن کاملThe Effective Cosmological Constant in Higher Order Gravity Theories
Fundamental issues as the determination of gravity vacuum state, the mechanism which led the early universe to the today observed large scale structures, and the prediction of what will be the fate of the whole universe are all connected to the determination of cosmological constant. Besides, from several points of view, it seems that Einstein’s theory of gravity must be generalized to higher–o...
متن کاملRecovering the effective cosmological constant in extended gravity theories
In the framework of extended gravity theories, we discuss the meaning of a time dependent “cosmological constant” and give a set of conditions to recover asymptotic de Sitter behaviour for a class of cosmological models independently of initial data. To this purpose we introduce a time–dependent (effective) quantity which asymptotically becomes the true cosmological constant. We will deal with ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physical Review D
سال: 2011
ISSN: 1550-7998,1550-2368
DOI: 10.1103/physrevd.84.075010