Related papers: Quantum and thermal pressures from light scalar fi…
If dark energy --- which drives the accelerated expansion of the universe --- consists of a light scalar field, it might be detectable as a "fifth force" between normal-matter objects, in potential conflict with precision tests of gravity.…
Theories of modified gravity where light scalars with non-trivial self-interactions and non-minimal couplings to matter-chameleon and symmetron theories-dynamically suppress deviations from general relativity in the solar system. On other…
Quantum theory predicts the existence of the Casimir force between macroscopic bodies, due to the zero-point energy of electromagnetic field modes around them. This quantum fluctuation-induced force has been experimentally observed for…
We consider the Casimir force betweeen two dielectric bodies described by the plasma model and between two infinitely thin plasma sheets. In both cases in addition to the photon modes surface plasmons are present in the spectrum of the…
A quantum field model for an experiment describes thermal fluctuations explicitly and quantum fluctuations implicitly, whereas a comparable continuous random field model would describe both thermal and quantum fluctuations explicitly. An…
We investigate the nontrivial interplay between geometry and temperature in the Casimir effect for the sphere-plate and cylinder-plate configurations. At low temperature, the thermal contribution to the Casimir force is dominated by this…
Additional scalar fields from scalar-tensor, modified gravity or higher dimensional theories beyond general relativity may account for dark energy and the accelerating expansion of the Universe. These theories have lead to proposed models…
A light scalar field framework of dark energy, sometimes referred to as quintessence, introduces a fifth force between normal matter objects. Screening mechanisms, such as the chameleon model, allow the scalar field to be almost massless on…
The mass of a scalar field mediating a fifth force is tightly constrained by experiments. We show, however, that adding a quartic self-interaction for such a scalar makes most tests much less constraining: the non-linear equation of motion…
We investigate the dependence of the thermal Casimir force between two graphene sheets on the drift velocity of the electrons in one graphene sheet. We show that the drift motion produces a measurable change of the thermal Casimir force due…
We present numerical $N$-body simulation studies of large-scale structure formation. The main purpose of these studies is to analyze the several models of dark matter and the role they played in the process of large-scale structure…
The discovery of the accelerating universe indicates strongly the presence of a scalar field which is not only expected to solve today's version of the cosmological constant problem, or the fine-tuning and the coincidence problems, but also…
A cosmic scalar field evolving very slowly in time can account for the observed dark energy of the Universe. Unlike a cosmological constant, an evolving scalar field also has local spatial gradients due to gravity. If the scalar field has a…
Studies of non-equilibrium dynamics of cosmological phase transitions may involve a scalar field interacting weakly with the energy-momentum tensor of a thermal plasma. At late times, when the scalar field is approaching equilibrium, it…
The chameleon is a scalar field whose mass depends on the density of its environment. Chameleons are necessarily coupled to matter particles and will excite transitions between atomic energy levels in an analogous manner to photons. When…
This paper studies the dynamics of scalar particle production, focusing on the presence of multiple fields and couplings in the medium. The interplay of various fields and couplings can influence the production rate, potentially…
We review new constraints on the Yukawa-type corrections to Newtonian gravity obtained recently from gravitational experiments and from the measurements of the Casimir force. Special attention is paid to the constraints following from the…
Scalar fields with a "chameleon" property, in which the effective particle mass is a function of its local environment, are common to many theories beyond the standard model and could be responsible for dark energy. If these fields couple…
The Casimir stress on two parallel plates in a de Sitter background corresponding to different metric signatures and cosmological constants is calculated for massless scalar fields satisfying Robin boundary conditions on the plates. Our…
Heat and work are fundamental concepts for thermodynamical systems. When these are scaled down to the quantum level they require appropriate embeddings. Here we show that the dependence of the particle spectrum on system size giving rise to…