Related papers: Vacuum energy density from the form factor bootstr…
We propose a proper definition of the vacuum expectation value of the stress energy tensor $\langle 0 | T_{\mu\nu} |0 \rangle$ for integrable quantum field theories in two spacetime dimensions, which is the analog of the cosmological…
We propose a thermodynamical definition of the vacuum energy density $\rho_{\rm vac}$, defined as $\langle 0| T_{\mu\nu} |0\rangle = - \rho_{\rm vac} \, g_{\mu\nu}$, in quantum field theory in flat Minkowski space in $D$ spacetime…
The cosmological constant (vacuum energy) problem is analyzed within the scope of quantum theories with UV-cut-off or fundamental length. Various cases associated with the appearance of the latter are considered both using the Generalized…
We consider extra compact dimensions as the origin of a cosmological universal energy density in the regular dimensions, with only graviton fields propagating in the compact space dimensions. The quantum zero point energy originating from…
The vacuum energy density is calculated for the $O(N)$ nonlinear sigma models in two dimensions. To obtain $\varepsilon_{vac}$ we assume that each point of the space in which non-perturbative f\/ields are determined can be replaced by a…
The energy density associated with Planck length is $\rho_{uv}\propto L_P^{-4}$ while the energy density associated with the Hubble length is $\rho_{ir}\propto L_H^{-4}$ where $L_H=1/H$. The observed value of the dark energy density is…
We study the vacuum zero point energy associated to a scalar field with an arbitrary mass and conformal coupling in a dS background. Employing dimensional regularization scheme, we calculate the regularized zero point energy density,…
The cosmological constant problem is reanalyzed by imposing the limitation of the number of degrees of freedom (d.o.f.) due to entropy bounds directly in the calculation of the energy density of a field theory. It is shown that if a quantum…
Lord Kelvin believed that the electromagnetic aether must also generate gravity. Presently, we have no methods to determine the density of the electromagnetic aether, or we say the $\Omega(1)$ substratum. Thus, we also suppose that vacuum…
Within the $\Lambda$CDM cosmological model, the absolute value of Einstein's cosmological constant $\Lambda$, sometimes expressed as the gravitating mass-energy density $\rho_\Lambda$ of the physical vacuum, is a fundamental constant of…
This paper presents a theoretical calculation of the vacuum energy density by summing the contributions of all quantum fields vacuum states which turns out to indicate that there seems to be a missing bosonic contribution in order to match…
The evolution of a vacuum component of the Universe is investigated in the quantum as well as the classical regimes. Probably our Universe has arisen as a vacuum fluctuation and very probably that it has had a high symmetry for Planckian…
We explore the idea that quantum vacuum energy $\rho_{\rm vac} $ is at the origin of Gravity. We formulate a gravitational version of the electromagnetic Casimir effect, and provide an argument for how gravity can arise from $\rho_{\rm vac}…
The accelerating expansion of the Universe points to a small positive vacuum energy density and negative vacuum pressure. A strong candidate is the cosmological constant in Einstein's equations of General Relativity. The vacuum dark energy…
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…
It is commonly believed that the vacuum energy problem points to the need for (1) a radically new formulation of gravitational physics and (2) a new principle which forces the vacuum stress-energy tensor (as measured by gravity) to be…
We consider that the cosmological constant is associated with the vacuum energy density of a particle physics model. In the path integral formalism of euclidean quantum gravity and in the background of the Robertson Walker metric we…
We have derived the quantum vacuum pressure P_vac as a primary entity, removing a trivial and a gauge terms from the cosmological constant-like part (the zeroth term) of the effective action for a free matter field. The quantum vacuum…
We propose that the expectation value of the stress energy tensor of the Standard Model should be given by $< T_{\mu \nu} > = \rho_\vac \eta_{\mu\nu}$, with a vacuum energy $\rho_\vac$ that differs from the usual "dimensional analysis"…
The vacuum energy density (Casimir energy) corresponding to a massless scalar quantum field living in different universes (mainly no-boundary ones), in several dimensions, is calculated. Hawking's zeta function regularization procedure…