Related papers: Spontaneous particle creation by oscillating compa…
We use time-evolutions of the linear perturbation equations to study the oscillations of rapidly rotating neutrons stars. Our models account for the buoyancy due to composition gradients and we study, for the first time, the nature of the…
Positively-curved, oscillatory universes are studied within the context of Loop Quantum Cosmology subject to a consistent semi-classical treatment. The semi-classical effects are reformulated in terms of an effective phantom fluid with a…
It is known that time-dependent vacuum expectation value of the background field may lead to abundant particle production in the early Universe. In supersymmetric theories bosons and fermions are produced in a correlated manner that depends…
We use the Bogoliubov formalism to study both, particles and gravitons creation at the reheating epoch, after a phase transition from inflation to a radiation dominated universe. The modes of the inflaton field fluctuations and the scalar…
The motion of a local source inducing small oscillations in the gravitational field is investigated and shown to exhibit pure rotational kinetic energy. Should the net affect of these slow, revolving oscillations cause large-scale rotations…
We propose that spontaneous particle--anti-particle pair creations from the discharged vacuum caused by the strong interactions in dense matter are major sources of $\gamma$-ray bursts. Two neutron star collisions or black hole-neutron star…
In this paper we calculate the particle creation as seen by a stationary observer in 3+1 de Sitter space. This particle creation is calculated using an observer dependent geometrically based definition of time which is used to quantize a…
This study explores the age-old quest to construct a geometric model of a quantum particle. While static classical particle models have largely been dismissed, the focus has now shifted to intricate dynamic models that hold the promise of…
The recently proposed states of low energy provide a well-motivated class of reference states for the quantized linear scalar field on cosmological Friedmann-Robertson-Walker spacetimes. The low energy property of a state is localized close…
We use wave packet mode quantization to compute the creation of massless scalar quantum particles in a colliding plane wave spacetime. The background spacetime represents the collision of two gravitational shock waves followed by trailing…
The quasiperiodic oscillations found in the three giant flares of soft gamma-ray repeaters observed to date have been interpreted as crustal oscillations caused by a starquake following a dramatic rearrangement of the stellar magnetic…
We study a quantum spherically symmetric object which is based on radial plasma oscillations. Such a plasmoid is supposed to exist in a dense plasma containing electrons, ions, and neutral particles. The method of creation and annihilation…
In this lecture, we give a first introduction to neutron stars, based on fundamental physical principles. After outlining their outstanding macroscopic properties, as obtained from observations, we infer the extreme conditions of matter in…
Binary star systems containing a neutron star or a black hole with an evolved, massive star are dynamically perturbed when the latter undergoes a supernova explosion. It is possible that the natal kick received by the newly-formed neutron…
We initiate numerical studies of differentially rotating magnetised (proto) neutron stars by studying - through construction from first principles - the coupling between an assumed differential rotation and an impressed magnetic field. For…
We consider a quantum field theory (QFT) model of neutrino oscillations in vacuum that attempts to take into account that the neutrino source particle and the neutrino detection particle both interact with their respective environments by…
A dark-energy-free cosmological model ($\Omega_{DE} \equiv 0$) based on gravitationally induced adiabatic particle creation is proposed. The thermodynamics of particle production yields an effective negative pressure that drives both…
We consider neutrino oscillations in vacuum in the framework of quantum field theory in which neutrino production and detection processes are part of a single Feynman diagram and the corresponding cross section is computed in the standard…
Gravitational waves are perturbations in the spacetime that propagate at the speed of light. The study of such phenomenon is interesting because many cosmological processes and astrophysical objects, such as binary systems, are potential…
We formulate the quantum field theory description of neutron-antineutron oscillations in the framework of canonical quantization, in analogy with the Bardeen--Cooper--Schrieffer (BCS) theory and the Nambu--Jona-Lasinio model. The physical…