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D. Palle

Publications and source records attributed to D. Palle.

16 recordsLinked to original sources
arXiv2005

On the vorticity of the Universe

Recent analyses of the first-year WMAP data claim large-scale asymmetry and anisotropy of the CMBR fluctuations. We argue that the covariant and gauge invariant treatment of density fluctuations formulated by Ellis and Bruni can explain the asymmetric and anisotropic WMAP data by including the vorticity of the Universe. It appears that the spatial gradients of the density contrast are proportional to the vorticity of the Universe, thus allowing measurements and quantifications of the magnitude and axis of the possible cosmological rotation.

astro-ph↗
arXiv2005

On the anomalous acceleration in the solar system

We study the impact of the cosmological environment on the solar gravitational system by the imbedding formalism of Gautreau. It appears that the cosmic mean-mass density and the cosmological constant give negligibly small contribution to gravity potentials. On the contrary, the cosmic acceleration beyond the Robertson-Walker geometry can considerably influence the curvature of spacetime in the solar system. The resulting anomalous constant acceleration towards the Sun is an order of magnitude smaller than that measured by Pioneer 10 and 11. However, it is larger than second order terms of potentials, thus well within the sensitivity of new gravity probes such as the LATOR mission.

astro-ph↗
arXiv2003

On the evolution of the cosmic-mass-density contrast and the cosmological constant

We study the evolution of the cosmic-mass-density contrast beyond the Robertson-Walker geometry including the small contribution of acceleration. We derive a second-order evolution equation for the density contrast within the spherical model for CDM collisionless fluid including the cosmological constant, the expansion and the non-vanishing vector of acceleration. While the mass-density is not seriously affected by acceleration, the mass-density contrast changes its shape at smaller redshifts even for a small amount of the acceleration parameter. This could help to resolve current controversial results in cosmology from measurements of WMAP, gravitational lensing, XMM X-ray cluster or type Ia supernovae data, etc.

astro-ph↗
arXiv2002

On heavy Majorana neutrinos as a source of the highest energy cosmic rays

Cosmic ray events beyond the Greisen-Zatsepin-Kuzmin cut-off represent a great challenge for particle physics and cosmology. We show that the physics of heavy Majorana neutrinos, well defined by their masses, cross sections and lifetimes, could explain the highest energy cosmic rays as a consequence of the galactic annihilation of heavy neutrinos as cold dark matter particles. Galactic nuclei accelerators, colliding neutron stars (black holes) or shocks from the collapsed objects could produce ultra high energy cosmic rays as heavy neutrinos beyond the mass threshold at an arbitrary cosmic distance. We comment and also analyse the DAMA results with regard to heavy neutrinos as galactic halo CDM particles.

hep-ph↗
arXiv2002

On the large-scale inhomogeneous Universe and the cosmological constant

We study the large-scale inhomogeneity of the Universe based on the averaging procedure of Buchert and Ehlers. The generalized Dyer-Roeder equation for the angular diameter distance of the inhomogeneous Universe is derived and solved for different cosmological models. We make a comparison of certain cosmic observables, such as the Hubble function, angular diameter distance,cosmological correction factor of homogeneous and inhomogeneous cosmological models, which are crucial ingredients in galaxy number counts and gravitational lenses.

astro-ph↗
arXiv2001

On the enhancement of the QCD running coupling

We show that the existence of the fundamental ultraviolet cut-off (minimal scale) fixed by weak interactions enhances the QCD running coupling evaluated at one quantum loop level, starting at the scale in the vicinity of the cut-off. The enhancement of the QCD running coupling could completely explain the observed anomalous TeVatron and HERA data. The QCD in the noncontractible space is not an asymptotically free gauge theory.

hep-ph↗
arXiv2000

On the quantum loop weak interaction corrections at high energies

We perform comparative analyses of quantum loop corrections to some observationally important two- and three-point Green functions within two distinct symmetry-breaking mechanisms. It appears that the existing high-energy data, neutrino experiments and present astrophysical and cosmological constraints strongly disfavour the Higgs mechanism, while the introduction of the noncontractible space as a symmetry-breaking mechanism can resolve all known problems and puzzles of fundamental interactions.

hep-ph↗
arXiv1999

On the lifetime of a cold dark matter particle and the cosmological diffuse photon background

We show that a Majorana heavy neutrino with a mass O(100TeV) is a good candidate particle for cold dark matter. It can be responsible for the majority of the cosmological diffuse photon background owing to lifetime of the order of O(10^(25)s), dominantly fixed by the radiative two-body decay. The lifetime is suppressed by two mechanisms: the leptonic GIM cancellation and the see-saw weak coupling suppression. As a fermion cold dark matter particle, a heavy neutrino favours the average mass density of the Universe constrained by the Einstein-Cartan cosmology.

hep-ph↗
arXiv1999

On the area distance and the Riemannian geometry

We study an area distance in the Riemannian spacetime with expansion, vorticity and acceleration. It is shown that this observable depends on expansion, deceleration and acceleration parameters to third order in redshift, as well as on vorticity. Thus, the considerable acceleration or vorticity of the Universe can substantially influence the standard astronomical distance calibrators.

astro-ph↗
arXiv1998

On primordial cosmological density fluctuations in the Einstein-Cartan gravity and COBE data

We study cosmological density fluctuations within a covariant and gauge-invariant fluid-flow approach for a perfect fluid in the Einstein-Cartan gravity and derive the corresponding Raychaudhuri type of inhomogeneous coupled differential evolution equations of the second order. It appears that the quantum fluctuations of spin trigger primordial density inhomogeneities at the scale of weak interactions. These inhomogeneities are then evolved precisely to the value measured be COBE mission at the scale of decoupling.

astro-ph↗
arXiv1997

Quantum mechanics in the noncontractible space

We show that the impact of the fundamental length in quantum mechanics can be studied within the formalism of Berry's geometrical phase with the line broadening as a resulting physical effect.

quant-ph↗
arXiv1997

A new contribution to the flavour-changing lepton- photon vertex

We show that the correct perturbation theory for mixed fermion states leads to nonvanishing contributions of the dimension-four vertex operators for flavour-changing transitions. Their contributions to the amplitude are of the same order of magnitude as the dimension- five vertex operators. Considerations are valid irrespective of the electroweak model. A complete and correct evaluation of the neutrino lifetime for particular electroweak models could be of greate importance in the theoretical cosmology and astrophysics.

hep-ph↗
arXiv1997

On certain relationships between cosmological observables in the Einstein-Cartan gravity

We show that in the Einstein-Cartan gravity it is possible to obtain a relation between Hubble's expansion and the global rotation (vorticity) of the Universe. Gravitational coupling can be reduced to dimensionless quantity of order unity, fixing the scalar mass density and the resulting negative cosmological constant at spacelike infinity. Current estimates of the expansion and rotation (see also astro-ph/9703082) of the Universe favour the massive spinning particles as candidate particles for cold and hot dark matter. Nodland and Ralston vorticity (Phys. Rev. Lett. 78 (1997) 3043) overestimates the value favoured by the Einstein-Cartan gravity for three orders of magnitude.

astro-ph↗
arXiv1997

Comment on Plaga's analysis of neutrino scattering Charm II data

We argue that the inclusion of the flavour-changing charged currents in the analysis of the Charm II data on neutrino- electron scattering could substantially change a fit of the effective couplings and makes impossible to draw any final conclusion on the Dirac or Majorana nature of neutrinos.

hep-ph↗
arXiv1994

Covariant model of a quarkonium with the funnel potential

The bound--state problem for the pion as a quarkonium with the funnel (Coulomb--plus--linear) interaction is solved in a framework that combines the bilocal approach to mesons with the covariant generalization of the instantaneous--potential model. The potential interaction leads to dynamical breaking of chiral symmetry. However, the Coulomb potential leads to ultraviolet divergences that must be subtracted. A careful choice of the renormalization prescription is needed in order to get the correct chiral limit. The mass, the lepton decay constant of the pion, as well as the pion decay width in two photons are calculated.

hep-ph↗