117946473
Black-hole creation in quantum cosmology
— It is proven that the probability of a black hole created from the de Sitter space-time background, at the WKB level, is the exponential of one quarter of the sum of the black hole and cosmological horizon areas, or the total entropy of the universe. This is true not only for the spherically symmetric cases of the Schwarzschild or Reissner-Nordstrom black holes, but also for the rotating case of the Kerr black hole and the rotating charged case of the Newman black hole. The de Sitter metric is the most probable evolution at the Planckian era of the universe.
121257961
Quantum creation of a Schwarzschild-de Sitter black hole
Using the Hartle-Hawking no-boundary proposal for the wave function of the universe, we can study the wave function and probability of a single Schwarzschild-de Sitter black hole created at the birth of the universe. The black hole originates from a gravitational instanton with conical singularities. The probability of a black hole creation is the exponential of one quarter of the sum of areas of the black hole and cosmological horizons. One quarter of this sum is the total entropy of the universe.
13157000
REAL TUNNELING AND BLACK HOLE CREATION
We discuss the Hawking theory of quantum cosmology with regard to approximation at the lowest order of the Planck constant. At this level, the quantum scenario will be reduced to its classical evolutions in real and imaginary times. We restrict our attention to the so-called real tunneling case. It can be shown that, even at this level, there still exist some quantum effects, the classical field equation may not hold at the transition surface. One can introduce the concept of constrained gravitational instanton. It may play some important role in the scenario of black hole creation in the inflationary background at the Planckian era of the universe. From the constrained gravitational instanton, the real tunneling can occur through different ways. Consequently, it will lead to the creation of different parts of the black hole spacetime in the de Sitter background. The global aspects of the black hole creation are discussed.
119348748
No-boundary codimension-two braneworld
Abstract The quantum creation probability and entropy of a 2-codimensional braneworld are calculated in the framework of no-boundary universe. The entropy can take an arbitrarily large value as the brane tensions increase, in violation of the conjectured “ N -bound” in quantum gravity, even for a 4-dimensional ordinary universe.
118836688
The Cosmological Constant in Quantum Cosmology
Hawking proposed that the cosmological constant is probably zero in quantum cosmology in 1984. By using the right configuration for the wave function of the universe, a complete proof is found very recently.
118822751
Dimensionality in the Freund–Rubin cosmology
Abstract In the n -dimensional Freund–Rubin model with an antisymmetric tensor field of rank s −1, the dimension of the external spacetime we live in must be min( s , n − s ). This result is a generalization of the previous result in the d =11 supergravity case, where s =4.
2474648
Neutrino masses and lepton-flavor-violating τ decays in the supersymmetric left-right model
In the supersymmetric left-right model, the light neutrino masses are given by the Type-II seesaw mechanism. A duality property of this mechanism indicates that there exist eight possible Higgs triplet Yukawa couplings which result in the same neutrino mass matrix. In this paper, we work out the one-loop renormalization group equations for the effective neutrino mass matrix in the supersymmetric left-right model. The stability of the Type-II seesaw scenario is briefly discussed. We also study the lepton-flavor-violating processes (tau -> mu gamma and tau -> e gamma) by using the reconstructed Higgs triplet Yukawa couplings.
10758180
Neutrino mixing and leptogenesis in type-II seesaw scenarios with left-right symmetry
Abstract We propose two type-II seesaw scenarios for the neutrino mass matrix in the left–right symmetric model, in which the Higgs triplet Yukawa coupling matrix takes the appealing Friedberg–Lee texture. We show that the nearly tri-bimaximal neutrino mixing pattern, which is especially favored by current neutrino oscillation data, can be obtained from both scenarios. We also show that the cosmological baryon number asymmetry can naturally be interpreted in these two scenarios via the flavor-independent leptogenesis mechanism.
126100739
Phenomenological analysis of J / psi suppression in h A processes
18431189
Nuclear Effects on Charmonium Production
$J/\psi$ and $\psi'$ production cross sections in fixed-target experiment is calculated, considering the contributions from both color-singlet and color-octet mechanisms.The results are applied to the investigations of the $J/\psi$ suppression and the $\psi'/\psi$ ratio problems in p-A collisions. The results agree with the experimental data as the $(c \bar c)-$nucleon absorption cross sections $\sigma_{abs}^8\simeq 10mb $ for $(c \bar c)_8$ and $\sigma_{abs}^1\simeq 0mb $ for $(c \bar c)_1$. The model is further used to investigate A-A collisions when comover absorption mechanism is also considered. It is found that the observed experiment data of $J/\psi$ and $\psi'/\psi$ ratio in S-U collisions and Pb-Pb collisions can not be explained consistently within this model. The possibility of QGP formation in S-U and Pb-Pb collisions is also discussed.
118448034
Neutrino Masses, Dark Matter and B-L Symmetry at the LHC
We establish a hybrid seesaw mechanism to explain small neutrino masses and predict cold dark matter candidate in the context of the B − L gauge symmetry extension of the Standard Model. In this model a new scalar doublet and two new fermion singlets are introduced at loop-level beyond the minimal Type I seesaw. The lightest particle inside the loop can be dark matter candidate. We study in detail the constraints from neutrino oscillation data, lepton flavor violating processes and cosmological observation. We also explore the predictions of the decays of the new charged scalars in each spectrum of neutrino masses and show the most optimistic scenarios to distinguish the spectra. We consider the pair production of the stable fermion associated with two observable SM charged leptons at �