Related papers: Relating a small decrease of (m_p/m_e) with cosmol…
Cosmic repulsion represented by a small positive value of the cosmological constant changes significantly properties of central gravitational fields at large distances, leading to existence of a static (or turnaround) radius where…
We propose a new approach to understand hierarchy problem for cosmological constant in terms of considering noncommutative nature of space-time. We calculate that vacuum energy density of the noncommutative quantum field theories in…
Last year I talked at this meeting about a possible time dependence of the QCD coupling constant $\alpha_s$. This year I shall look into the problem once more, without fully repeating the arguments given last year. Astrophysical indications…
A mechanism is introduced to reduce a large cosmological constant to a sufficiently small value consistent with observational upper limit. The basic ingradient in this mechanism is a distinction which has been made between the two unit…
The fundamental constants of electromagnetism, gravity and quantum mechanics can be related empirically by the numerical approximation $\ln(V_e/V_P)\approx \alpha^{-1}$, where $\alpha$ is the low energy value of the electromagnetic fine…
In this paper we discuss a model in which the energy density, corresponding to the effective cosmological constant, after the $SU(2)\times U(1)$ symmetry breaking appears to be of the desired order of $10^{-48}\div 10^{-47} GeV^{4}$. The…
The accelerating expansion of the Universe points to a small positive value for the cosmological constant or vacuum energy density. We discuss recent ideas that the cosmological constant plus LHC results might hint at critical phenomena…
We point out that the expansion of the universe leads to a cosmological time evolution of the vacuum expectation of the Higgs boson. Within the standard model of particle physics, the cosmological time evolution of the vacuum expectation of…
The cosmological constant problem is examined under the assumption that the extrinsic curvature of the space-time contributes to the vacuum. A compensation mechanism based on a variable cosmological term is proposed. Under a suitable…
Astronomical observations have a unique ability to determine the laws of physics at distant times in the universe. They, therefore, have particular relevance in answering the basic question as to whether the laws of physics are invariant…
I argue that a solution to the cosmological constant problem is to assume that the expectation value of the quantum vacuum stress-energy tensor is proportional to the metric tensor with a negative energy density and positive pressure. This…
Within conventional big bang cosmology, it has proven to be very difficult to understand why today's cosmological constant is so small. In this paper, we show that a cyclic model of the universe can naturally incorporate a dynamical…
The values of the fundamental constants such as $\mu = m_P/m_e$, the proton to electron mass ratio and $\alpha$, the fine structure constant, are sensitive to the product $\sqrt{\zeta_x^2(w+1)}$ where $\zeta_x$ is a coupling constant…
We introduce a dynamical model to reduce a large cosmological constant to a sufficiently small value. The basic ingredient in this model is a distinction which has been made between the two unit systems used in cosmology and particle…
A simple model is introduced in which the cosmological constant is interpreted as a true Casimir effect on a scalar field filling the universe (e.g. $\mathbf{R} \times \mathbf{T}^p\times \mathbf{T}^q$, $\mathbf{R} \times \mathbf{T}^p\times…
The observed small value of cosmological constant can be naturally related with the scale of breaking down supersymmetry in agreement with other evaluations in particle physics.
Quantum field theory predicts that vacuum energy (or what is the same, cosmological constant) should be 50-100 orders of magnitude larger than the existing astronomical limit. A very brief review of possible solutions of this problem is…
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…
We show that a tiny but non-zero positive cosmological constant, which has been strongly suggested by the recent astronomical observations on supernovae and CMBR, may change notably the behaviors of the ultrahigh energy cosmic ray…
The value of the cosmological constant arising from a crystalline model for vacuum cosmic space with lattice parameter of the order of the neutron radius [1] has been calculated. The model allows to solve, in an easy way, the problem of the…