619 research outputs found

    Evolution of thick domain walls in inflationary and p=wρp=w\rho universe

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    We study the evolution of thick domain walls in the different models of cosmological inflation, in the matter-dominated and radiation-dominated universe, or more generally in the universe with the equation of state p=wρp=w\rho. We have found that the domain wall evolution crucially depends on the time-dependent parameter C(t)=1/(H(t)ÎŽ0)2C(t)=1/(H(t)\delta_0)^2, where H(t)H(t) is the Hubble parameter and ÎŽ0\delta_0 is the thickness of the wall in flat space-time. For C(t)>2C(t)>2 the physical thickness of the wall, a(t)ÎŽ(t)a(t)\delta(t), tends with time to ÎŽ0\delta_0, which is microscopically small. Otherwise, when C(t)≀2C(t) \leq 2, the wall steadily expands and can grow up to a cosmologically large size.Comment: 15 pages, 9 figure

    Difference between radiative transition rates in atoms and antiatoms

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    We demonstrate that CP violation results in a difference of the partial decay rates of atoms and antiatoms. The magnitude of this difference is estimated.Comment: 5 pages, 5 figure

    Baryogenesis from Gravitational Decay of TeV-Particles in Theories with Low Scale Gravity

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    In models with the fundamental gravity scale in the TeV range, early cosmology is quite different from the standard picture, because the universe must have arisen at a much lower temperature and the electroweak symmetry was probably never restored. In this context, baryogenesis appears to be problematic: if the involved physics is essentially that of the Standard Model, ``conventional'' non-conserving baryon number processes are completely negligible at such low temperatures. In this paper we show that the observed matter-antimatter asymmetry of the universe may be generated by gravitational decay of TeV-mass particles: such objects can be out of equilibrium after inflation and, if their mass is of the same order of magnitude as the true quantum gravity scale, they can quickly decay through a black hole intermediate state, violating global symmetries, in particular, baryon number. In this context, we take advantage of the fact that the ``Sakharov conditions'' for baryogenesis can be more easily satisfied with a low fundamental scale of gravity.Comment: 18 pages, added reference

    Charmed penguin versus BAU

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    Since the Standard Model most probably cannot explain the large value of CP asymmetries recently observed in D-meson decays we propose the fourth quark-lepton generation explanation of it. As a byproduct weakly mixed leptons of the fourth generation make it possible to save the baryon number of the Universe from erasure by sphalerons. An impact of the 4th generation on BBN is briefly discussed.Comment: 13 pages, 3 figures, version to be published in JETP Letter

    Condensation of charged bosons in plasma physics and cosmology

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    The screening of impurities in plasma with Bose-Einstein condensate of electrically charged bosons is considered. It is shown that the screened potential is drastically different from the usual Debye one. The polarization operator of photons in plasma acquires infrared singular terms at small photon momentum and the screened potential drops down as a power of distance and even has an oscillating behavior, similar to the Friedel oscillations in plasma with degenerate fermions. The magnetic properties of the cosmological plasma with condensed W-bosons are also discussed. It is shown that W-bosons condense in the ferromagnetic state. It could lead to spontaneous magnetization of the primeval plasma. The created magnetic fields may seed galactic and intergalactic magnetic fields observed in the present-day universe.Comment: 9 pages, invited talk at the International Seminar "Quarks 2010", Kolomna, Russia, June, 6-12, 201
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