Related papers: Vacuum condensates and `ether-drift' experiments
In principle, by accepting the idea of a non-zero vacuum energy, the physical vacuum of present particle physics might represent a preferred reference frame. By treating this quantum vacuum as a relativistic medium, the non-zero…
We re-consider the idea that quantum fluctuations might reflect the existence of an 'objective randomness', i.e. a basic property of the vacuum state which is independent of any experimental accuracy of the observations or limited knowledge…
The condensation of elementary quanta and their macroscopic occupation of the same quantum state, say k=0 in some reference frame Sigma, is the essential ingredient of the degenerate vacuum of present-day elementary particle physics. This…
Basic foundational aspects of both quantum theory and relativity might induce to represent the physical vacuum as an underlying highly turbulent fluid. By explicit numerical simulations, we show that a form of statistically isotropic and…
Even though the concept has evolved and if the designation as aether is improperly regarded as outdated, nobody today considers that the vacuum is empty. However, the nature and the properties of the substratum, which permeates the entire…
In the data of the ether-drift experiments there might be sizable fluctuations superposed on the smooth sinusoidal modulations due to the Earth's rotation and orbital revolution. These fluctuations might reflect the stochastic nature of the…
According to several authors, gravity might be a long-wavelength phenomenon emerging in some 'hydrodynamic limit' from the same physical, flat-space vacuum viewed as a form of superfluid medium. In this framework, light might propagate in…
In quantum theory the vacuum is defined as a state of minimum energy that is devoid of particles but still not completely empty. It is perhaps more surprising that its definition depends on the geometry of the system and on the trajectory…
Models with extra space-time dimensions produce, tipically, a 4D effective theory whose vacuum is not exactly Lorentz invariant but can be considered a physical medium whose refractive index is determined by the gravitational field. This…
The current state of research on vortices carried by quantum droplets (QDs) has predicted their existence, in the stable form, in two- and three-dimensional free-space binary Bose-Einstein condensates (BECs) and dipolar BECs. These…
Cosmology is investigated within a new, scalar theory of gravitation, which is a preferred-frame bimetric theory with flat background metric. Before coming to cosmology, the motivation for an " ether theory " is exposed at length; the…
The experimental data, as well as theoretical considerations allow (and, in some cases, require) the Universe at present to rest in a false vacuum, whose approximate stability imposes constraints on the model parameters. Under very general…
The quantum vacuum constitutes a fascinating medium of study, in particular since near-future laser facilities will be able to probe the nonlinear nature of this vacuum. There has been a large number of proposed tests of the low-energy,…
The many experimental puzzles of solid hydrogen, that seem to defy the generally accepted view of condensed matter, are shown to be a rather straightforward consequence of a new approach to condensed matter physics, that takes into account…
According to some authors, gravity might be an emergent phenomenon in a fundamentally flat space-time. In this case the speed of light in the vacuum would not coincide exactly with the basic parameter "c" entering Lorentz transformations…
The phenomenon of emergent physics in condensed-matter many-body systems has become the paradigm of modern physics, and can probably also be applied to high-energy physics and cosmology. This encouraging fact comes from the universal…
For a long time, people believe that all possible states of matter are described by Landau symmetry-breaking theory. Recently we find that string-net condensation provide a mechanism to produce states of matter beyond the symmetry-breaking…
For a quantum field in a curved background the choice of the vacuum state is crucial. We exhibit a vacuum state in which the expectation values of the energy and pressure allow an intuitive interpretation. We apply this general result to…
We present a general theory of drag on a condensate due to interactions with a moving thermal bath of non-condensate particles, adapted from previous theory of equilibration of a condensate in a trap. This theory can be used to model the…
It is shown that the vacuum condensate induced by many phenomena behaves as a perfect fluid which, under particular conditions, has zero or negative pressure. In particular, the condensates of thermal states, of fields in curved space and…