Related papers: False vacuum as an unstable state: possible cosmol…
The cosmological constant problem can be understood as the failure of the decoupling principle behind effective field theory, so that some quantities in the low-energy theory are extremely sensitive to the high-energy properties. While this…
Whether the Standard Model electroweak vacuum is stable, metastable or unstable depends crucially on the top mass (and, to a lesser extent, on other measurable quantities). These topics are reviewed and updated by taking into account the…
We study particles creation in arbitrary space-time dimensions by external electric fields, in particular, by fields, which are acting for a finite time. The time and dimensional analysis of the vacuum instability is presented. It is shown…
This contribution reviews recent work on a new approach to the cosmological constant problem, which starts from the macroscopic behavior of a conserved relativistic microscopic variable q. First, the statics of the vacuum energy density is…
It is proposed that the Higgs vacuum possesses a small-scale structure that can explain the large discrepancy between the predicted electroweak vacuum energy density and the observed cosmological constant. An effective Lagrangian…
We construct the instantaneous vacuum state for a quantum scalar field coupled to another classical scalar field as described in [1]. We then compare it with the state of low energy constructed for a particular solution. We show that under…
Instabilities of equilibrium quantum mechanics are common and well-understood. They are manifested for example in phase transitions, where a quantum system becomes so sensitive to perturbations that a symmetry can be spontaneously broken.…
The decay of a bound state weakly-coupled to a non-Hermitian tight-binding unstable continuum, i.e. a continuum of states comprising energies with positive imaginary part, is theoretically investigated. As compared to quantum decay in an…
Two sides of cosmological constant problem are discussed: a mysterious compensation of all contributions to vacuum energy with the accuracy of 100-50 orders of magnitude and a surprising equality of a constant vacuum energy density to the…
A new mechanism of adjustment of vacuum energy down to the observed value from an initially huge one is considered. The mechanism is based on a very strong variation of the gravitational coupling constant in very early universe. The model…
Observation indicates that the expansion of the Universe is accelerating and favours a dynamical cosmological constant, \Lambda(t). We consider the possibility that this is due to a scalar field which has undergone a very recent phase…
Vacuum decay posits that the universe's apparent vacuum is metastable and could transition to a lower-energy state. According to current physics models, if such a transition occurred in any location, a region of "true vacuum" would…
Physicists have speculated about the properties of the quantum vacuum for at least 85 years; however, only recently have they understood the quantum vacuum sufficiently well to begin making testable predictions. Specifically, using…
We consider a formalism to describe the false-vacuum decay of a scalar field in gauge theories in non-perturbative regimes. We find that the larger the gauge coupling with respect to the self-coupling of the scalar, the shallower the local…
The high-quality cosmological data, which became available in the last decade, have thrusted upon us a rather preposterous composition for the universe which poses one of the greatest challenges theoretical physics has ever faced: the…
Modern astronomical observations in cosmology provide increasingly strong evidence that the expansion of the Universe is accelerating. Explanations of the cosmic acceleration within the framework of general relativity use the hypothesis…
We consider dynamics of spacetime volume-filling form fields with "wrong sign" kinetic terms, such as in so-called Type-II$^*$ string theories. Locally, these form fields are just additive renormalizations of the cosmological constant. They…
A metastable state, or a false vacuum, is not an eigenstate of the Hamiltonian in quantum field theory. Its energy density has a non-zero imaginary part equal to its decay width. Therefore, supersymmetry cannot be exact in the false vacuum.…
If a theory has more than one classically stable vacuum, quantum tunneling and thermal jumps make the transition between the vacua possible. The transition happens through a first order phase transition started by nucleation of a bubble of…
Experimental data suggest that the Higgs potential has a lower ground state at high field values. Consequently, decaying from the electroweak to the true vacuum nucleates bubbles that expand rapidly and can have dire consequences for our…