A phase space for gravitational radiation

We give a new definition, based on considerations of well-posedness for a certain asymptotic initial value problem, of the phase space for the radiative degrees of freedom of the gravitational field in exact General Relativity. This space fibres over the space of final states, with the fibres being the purely radiative degrees of freedom. The symplectic form is rigorously identified.The infrared sectors are shown to be the level surfaces of a moment map of an action of the quotient group Supertranslations/Translations. A similar result holds for Electromagnetism in Minkowski space.     

Geometric phase shift for detection of gravitational radiation

A geometrical phase shift is predicted for a light beam propagating in the field of a gravitational wave. Gravitational radiation detection experiments are proposed using this new effect, and the corresponding estimates are given.     

Bursts of gravitational radiation from superconducting cosmic strings and the neutrino mass spectrum

Berezinsky, Hnatyk and Vilenkin showed that superconducting cosmic strings could be central engines for cosmological gamma-ray bursts and for producing the neutrino component of ultra-high energy cosmic rays. A consequence of this mechanism would be that a detectable cusp-triggered gravitational wave burst should be released simultaneously with the γ-ray surge. If contemporary measurements of both γ and ν radiation could be made for any particular source, then the cosmological time-delay between them might be useful for putting unprecedentedly tight bounds on the neutrino mass spectrum. Such measurements could consistently verify or rule out the model, since strictly correlated behaviour is expected for the duration of the event and for the time variability of the spectra.     

Hawking radiation from the with a global monopole via Schwarzschild black hole gravitational anomaly

This paper derives the Hawking flux from the Schwarzschild black hole with a global monopole by using Robinson and Wilczek＇s method. Adopting a dimensional reduction technique, it can describe the effective quantum field in the （3 ＋ 1）-dimensional global monopole background by an infinite collection of the （1 ＋ 1）-dimensional massless fields if neglecting the ingoing modes near the horizon, where the gravitational anomaly can be cancelled by the （1 ＋ 1）- dimensional black body radiation at the Hawking temperature.     

Post-Newtonian gravitational radiation from binary stars

A method is presented for evaluating post-Newtonian orbital corrections to the orbital-period decrease of a relativistic binary, by using previous results on the gravitational-radiation luminosity of a bounded source and the binary's relative motion. The method is based on an energy-balance equation, whose validity to post-Newtonian accuracy is not proved here, but, in view of recent theoretical results on the classical energy-balance equation, seems to be quite reasonable, and, in view of the available observational data, is practically correct. In the case of the binary pulsar PSR 1913 + 16 the proposed relative orbital correction amounts to 10^–6 of the current observational uncertainty, thus greatly favoring the predictions of the classical quadrupole formula.     

Analogy between first-order phase transitions and blackbody radiation

The analogy between blackbody radiation and a phase equilibrium between vapor and liquid is drawn by deriving the Clapeyron equation in which the two probability distributions of blackbody radiation play the role of the two phases. The pressure of one of these distributions, which becomes negative at sufficiently high photon energies, is analogous to a negative pressure tending to break up a liquid. A similar type of critical phenomenon should be observed for blackbody radiation.     

High-density QCD phase transitions inside neutron stars: Glitches and gravitational waves

In this article, the cluster–cluster interaction between α-clusters in ¹⁶O and ²⁰Ne is studied theoretically. Using the generalized Nikiforov–Uvarov (NU) technique, the clusterization energy for these nuclei is calculated. Based on the obtained results, one can find out that the clustering phenomenon does not take place neither at the ground state, nor at the excited states of these nuclei and it is more probable at energies among excited levels. It is shown that the formulation presented for the clustering phenomenon reproduces the results obtained in previous experimental and theoretical attempts. It is worth mentioning that the consistency of the results with the previous experimental and theoretical predictions for clustering phenomenon in ¹⁶O and ²⁰Ne indicates the reliability of this formulation for various types of light α-conjugate nuclei, such as ⁸Be, ¹²C, ²⁴Mg and so on.     

Characteristic radiation due to the phase transitions latent energy

It is discovered that under the phase transition of the first kind a part of the latent heat converts into infrared radiation with frequences close to the new appearing bonds energies. The experiments were carried out on water crystallization and vapor condensation.     

Percival variational principle for invariant measures and commensurate-incommensurate phase transitions in one-dimensional chains

We prove for a one-dimensional system of classical particles with potential energy, $$U_{\alpha ,\gamma } = \sum\limits_n {\left[ {\alpha V(x_n ) + F(x_{n + 1} - x_n - \gamma )} \right]} $$ , the existence of such a smooth function γ(α), 0≦α≦α₀(ω) that the system with potential energyU _αγ(α) has the equilibrium state at the temperatureT=0. This is the incommensurate phase with the ratio of periods equal to the prescribed irrational number ω, badly approximated by rational ones. A simple geometric condition for the invariant curve of the corresponding dynamical system is established under which it is the support of the invariant measure minimizing Percival's energy functional.     

Emergent universe from scale invariant two measures theory

The dilaton-gravity sector of a linear in the scalar curvature, scale invariant Two Measures Field Theory (TMT), is explored in detail in the context of closed FRW cosmology and shown to allow stable emerging universe solutions. The model possesses scale invariance which is spontaneously broken due to the intrinsic features of the TMT dynamics. We study the transition from the emerging phase to inflation, and then to a zero cosmological constant phase. We also study the spectrum of density perturbations and the constraints that impose on the parameters of the theory.     

On structural phase transitions from a hypothetical phase

Examples known so far of structural phase transitions which can be treated as an instability of a hypothetical parent phase are enumerated. Physical requirements for being reasonable to consider such hypothetical phase are pointed out. The possibility of using this concept for explanation of successive structural phase transitions in Rochelle salt and langbeinites is discussed.The author thanks Dr. V.Janovec for many valuable remarks to this paper.     

Possible gravitational radiation detection using the geometric phase of a light beam

An effect of geometrical phase shift is predicted for a light beam propagating in the field of a gravitational wave. For the beam travelling orthogonally to the direction of propagation of the gravitational wave from an observer and returning back after being reflected, this phase is shown to grow proportionally toL/ whereL is the distance between the observer and reflecting system, and the characteristic wavelength of the gravitational wave packet (for light propagating parallel or antiparallel to the gravitational wave, the geometric phase shift is absent). Gravitational radiation detection experiments are proposed using this new effect, the corresponding estimates being given.On leave of absence from: Peoples' Friendship University, Moscow, RussiaOn leave of absence from: Krasnoyarsk State University, Krasnoyarsk, Russia     

Hawking radiation from gravity''s rainbow via gravitational anomaly

Based on the anomaly cancellation method, initiated by Robinson and Wilczek, we investigates Hawking radiation from the modified Schwarzschild black hole from gravity＇s rainbow from the anomaly point of view. Unlike the general Schwarzschild space-time, the metric of this black hole depends on the energies of probes. The obtained result shows to restore the underlying general covariance at the quantum level in the effective field, the covariant compensating flux of energy-momentum tensor, which is related to the energies of the probes, should precisely equal to that of a （1 ＋ 1）-dimensional blackbody at the Hawking temperature.