منابع مشابه
Cosmological Constant ?
We prove that a class of one-loop partition functions found by Dienes, giving rise to a vanishing cosmological constant to one-loop, cannot be realized by a consistent lattice string. The construction of non-supersymmetric string with a vanishing cosmological constant therefore remains as elusive as ever. We also discuss a new test that any one-loop partition function for a lattice string must ...
متن کاملUnimodular relativity and cosmological constant
Unimodular relativity is a theory of gravity and space–time with a fixed absolute space–time volume element, the modulus, which we suppose is proportional to the number of microscopic modules in that volume element. In general relativity an arbitrary fixed measure can be imposed as a gauge condition, while in unimodular relativity it is determined by the events in the volume. Since this seems t...
متن کاملDuality and the cosmological constant
A dynamical theory is studied in which a scalar field φ in Einstein-Minkowski space is coupled to the four-velocity Nμ of a preferred inertial observer in that space. As a consistent requirement on this coupling we study a principle of duality invariance of the dynamical mass-term of φ at some universal length in the smalldistance regime. In the large-distance regime duality breaking can be int...
متن کاملQuintessence and the cosmological constant
The idea of quintessence originates from an attempt to understand the smallness of the “cosmological constant” or dark energy in terms of the large age of the universe [1]. As a characteristic consequence, the amount of dark energy may be of the same order of magnitude as radiation or dark matter during a long period of the cosmological history, including the present epoch. Today, the inhomogen...
متن کاملEffective cosmological “constant” and quintessence
In this paper we present exactly solved extended quintessence models; furthermore, through a dynamical effective Q-cosmological ”constant”, we recover some of the Λ decaying cases found in the literature. Finally we introduce a sort of complementarity between the Q-dominated or Λdominated expansions of the Universe. e-mail addresses: [email protected] [email protected]
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: Universe
سال: 2017
ISSN: 2218-1997
DOI: 10.3390/universe3020043