Abstract. Combining certain identities for modular forms due to Igusa with Schottky-Jung relations, we study the cosmological constant for the recently proposed ansatz for the chiral superstring measure in genus 5. The vanishing of this cosmological constant turns out to be equivalent to the long-conjectured vanishing of a certain explicit modular form of genus 5 on the moduli of curves M5, and...

In a recent striking discovery, Dunlop et al [1] observed a galaxy at redshift z=1.55 with an estimated age of 3.5 Gyr. This is incompatible with age estimates for a flat matter dominated universe unless the Hubble constant is less than 45kmsMpc. While both an open universe, and a universe with a cosmological constant alleviate this problem, I argue here that this result favors a non-zero cosmo...

In quantum field theory the parameters of the vacuum action are subject to renormalization group running. In particular, the “cosmological constant” is not a constant in a quantum field theory context, still less should be zero. In this paper we continue with previous work, and derive the particle contributions to the running of the cosmological and gravitational constants in the framework of t...

In this letter we will revise the steps followed by A. Einstein when he first wrote on cosmology from the point of view of the general theory of relativity. We will argue that his insightful line of thought leading to the introduction of the cosmological constant in the equations of motion has only one weakness: The constancy of the cosmological term, or what is the same, its independence of th...

We use the Gurvits, Kellermann, & Frey compact radio source angular size versus redshift data to place constraints on cosmological model parameters in models with and without a constant or time-variable cosmological constant. The resulting constraints are consistent with but weaker than those determined using current supernova apparent magnitude versus redshift data. Subject headings: cosmology...

Some generalized soliton solutions of the cosmological Einstein-Rosen type defined in the space-time region t 2;prin terms of canonical coordinates are considered. Vacuum solutions are studied and interpreted as cosmological models. Fluid solutions are also considered and are seen to represent inhomogeneous cosmological models that become homogeneous at t 00. A subset of these evolve toward iso...

We investigate the evolution of a universe with a decaying cosmological term (vacuum energy) that is assumed to be a function of the scale factor. In this model, while the cosmological term increases to the early universe, the radiation energy density is lower than the model with the cosmological "constant". We find that the effects of the decaying cosmological term on the expansion rate at the...

We propose, based on brane cosmology, an explicit relation R = MPlR 2 extra of the radius of the observed brane Universe and the extra dimensions for solving both the hierarchy problem and the cosmological constant problem without fine-tuning. This relation associates the dark energy (i.e., cosmic acceleration) in the cosmological physics with the electroweak scale in particle physics, thereby ...

In quantum field theory, the vacuum action is subject to renormalization and to the renormalization group running. Consequently, the “cosmological constant” is not a constant, still less should be zero. In this paper we continue with previous work, and derive the contributions of the light particles to the running of the cosmological and gravitational constants in the Standard Model, from the c...

In this article the cosmological constant problems, as well as the astronomical evidence for a cosmologically significant homogeneous exotic energy density with negative pressure (quintessence), are reviewed for a broad audience of physicists and mathematicians. After a short history of the cosmological term it is explained why the (effective) cosmological constant is expected to obtain contrib...