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Davor Palle

Publications and source records attributed to Davor Palle.

24 records · Page 2Linked to original sources
arXiv2009

On Dyson-Schwinger equations and the number of fermion families

We study Dyson-Schwinger equations for propagators of Dirac fermions interacting with a massive gauge boson in the ladder approximation. The equations have the form of the coupled nonlinear integral Fredholm equations of the second kind in the spacelike domain. The solutions in the timelike domain are completely defined by evaluations of integrals of the spacelike domain solutions. We solve the equations and analyze the behavior of solutions on the mass of the gauge boson, the coupling constant, and the ultraviolet cutoff. We find that there are at least two solutions for the fixed gauge boson mass, coupling, and the ultraviolet cutoff, thus there are at least two fermion families. The zero-node solution represents the heaviest Dirac fermion state, while the one-node solution is the lighter one. The mass gap between the two families is of the order of magnitude observed in nature.

hep-ph↗
arXiv2006

On gravitational lensing by quadrupole potentials

We study gravitational lensing by quadrupole potentials within the linearized gravity approximation and the integration over the unperturbed photon trajectory. It is well known that the quadrupole potential contribution to the deviation angle is much smaller than that of the monopole one. We show, however, that quadrupole potentials can change the photon polarization vector, but there is no contribution from the monopole term to the first order. The effect is maximal when the axis of the quadrupole is tangential to the photon trajectory and it is proportional to the frequency(rate) of the quadrupole moment of the deflector. The second order correction of the monopole potential to the polarization is canceled away by the renormalization of the polarization vector.

astro-ph↗
arXiv2006

Breaking the scale invariance of the primordial spectrum or not: the new WMAP data

It seems that new WMAP data requires a fit with a primordial spectrum containig small negative tilt index in addition to the featureless Harrison-Zeldovich- Peebles spectrum thus implying a broken scale invariance. We show that the data could be otherwise interpreted by a scale invariant primordial spectrum with the scale non-invariant evolution of density contrast using the Press-Schechter formalism. The estimate of the acceleration parameter, as a source of the inhomogeneity of spacetime, is made by searching for the minima of the deviation measure defined by the Press-Schechter mass functions for this interpretation compared to the assumptions implicit in the WMAP fit.

astro-ph↗
arXiv2005

Comment on the paper of Jaffe et al (astro-ph/0503213) on evidence of vorticity and shear of the Universe

We show that recent results in the paper of Jaffe et al on evidence of vorticity and shear of the Universe are incorrect. They fit WMAP data with certain Bianchi model which is known to have a vanishing vorticity. The performed fit of the shear is not reliable because the respective formula seems not to be gauge invariant. We suggest a theoretical framework to analyze asymmetric large scale WMAP data.

astro-ph↗