Growth Histories in Bimetric Massive Gravity

We perform cosmological perturbation theory in Hassan-Rosen bimetric gravity for general homogeneous and isotropic backgrounds. In the de Sitter approximation, we obtain decoupled sets of massless and massive scalar gravitational fluctuations. Matter perturbations then evolve like in Einstein gravity. We perturb the future de Sitter regime by the ratio of matter to dark energy, producing quasi-de Sitter space. In this more general setting the massive and massless fluctuations mix. We argue that in the quasi-de Sitter regime, the growth of structure in bimetric gravity differs from that of Einstein gravity.Comment: 28 pages + appendix, 11 figure

Submanifolds in five-dimensional pseudo-Euclidean spaces and four-dimensional FRW universes

Equations for submanifolds, which correspond to embeddings of the four-dimensional FRW universes in five-dimensional pseudo-Euclidean spaces, are presented in convenient form in general case. Several specific examples are considered.Comment: 7 pages, LaTeX, the mathematical part of this paper is based on the withdrawn preprint arXiv:1012.0320 [gr-qc

Phase diagram of dense neutral three-flavor quark matter

We study the phase diagram of dense, locally neutral three-flavor quark matter as a function of the strange quark mass, the quark chemical potential, and the temperature, employing a general nine-parameter ansatz for the gap matrix. At zero temperature and small values of the strange quark mass, the ground state of matter corresponds to the color-flavor-locked (CFL) phase. At some critical value of the strange quark mass, this is replaced by the recently proposed gapless CFL (gCFL) phase. We also find several other phases, for instance, a metallic CFL (mCFL) phase, a so-called uSC phase where all colors of up quarks are paired, as well as the standard two-flavor color-superconducting (2SC) phase and the gapless 2SC (g2SC) phase.Comment: 14 pages, 11 figures, references added; the version accepted for publication in Nucl. Phys.

Can Theta/N Dependence for Gluodynamics be Compatible with 2 pi Periodicity in Theta ?

In a number of field theoretical models the vacuum angle \theta enters physics in the combination \theta/N, where N stands generically for the number of colors or flavors, in an apparent contradiction with the expected 2 \pi periodicity in \theta. We argue that a resolution of this puzzle is related to the existence of a number of different \theta dependent sectors in a finite volume formulation, which can not be seen in the naive thermodynamic limit V -> \infty. It is shown that, when the limit V -> \infty is properly defined, physics is always 2 \pi periodic in \theta for any integer, and even rational, values of N, with vacuum doubling at certain values of \theta. We demonstrate this phenomenon in both the multi-flavor Schwinger model with the bosonization technique, and four-dimensional gluodynamics with the effective Lagrangian method. The proposed mechanism works for an arbitrary gauge group.Comment: minor changes in the discussion, a few references are adde

Thermal rates for baryon and anti-baryon production

We use a form of the fluctuation-dissipation theorem to derive formulas giving the rate of production of spin-1/2 baryons in terms of the fluctuations of either meson or quark fields. The most general formulas do not assume thermal or chemical equilibrium. When evaluated in a thermal ensemble we find equilibration times on the order of 10 fm/c near the critical temperature in QCD.Comment: 22 pages, 4 tables and 2 figures, REVTe

Updated resonance photo-decay amplitudes to 2 GeV

We present the results of an energy-dependent and set of single-energy partial-wave analyses of single-pion photoproduction data. These analyses extend from threshold to 2 GeV in the laboratory photon energy, and update our previous analyses to 1.8 GeV. Photo-decay amplitudes are extracted for the baryon resonances within this energy range. We consider two photoproduction sum rules and the contributions of two additional resonance candidates found in our most recent analysis of $\pi N$ elastic scattering data. Comparisons are made with previous analyses.Comment: Revtex, 26 pages, 3 figures. Postscript figures available from ftp://clsaid.phys.vt.edu/pub/pr or indirectly from http://clsaid.phys.vt.edu/~CAPS

Uso de semivariograma escalonado na variabilidade espacial da textura do solo em uma área de terra preta arqueológica sob floresta em Manicoré - AM

Os solos predominantes na região Amazônica pertencem à classe dos Latossolos e Argissolos, caracterizado por seu alto grau de intemperismo e baixa fertilidade natural, em contraste, ocorrem às Terras Pretas Arqueológicas com elevada fertilidade natural e alto teor de matéria orgânica, coloração escura, presença de artefatos cerâmicos indígenas incorporados a matriz do horizonte superficiais do solo. O objetivo deste trabalho foi investigar o uso de semivariograma escalonado na variabilidade espacial da textura do solo em uma área de terra preta arqueológica sob floresta em Manicoré, AM. A área em estudo encontra-se na região do município de Manicoré – AM, no km 210 a 30 km da comunidade do Santo Antônio do Matupi, as margens da BR 230, rodovia transamazônica. As áreas são de Terra Pretas Arqueológicas (TPA) sob Floresta nativa, onde foi estabelecido o mapeamento de uma malha de 6 x 6 m, nas profundidades de amostragem 0,0 - 0,05, 0,05 - 0,10 e 0,10 - 0,20 m, totalizando 88 pontos georreferenciados totalizando 264 pontos amostrais nas 3 profundidades. Em seguida realizou-se analise textural para determinar areia, silte e argila. Os resultados foram tratados estaticamente por meio de analise descritivas e geoestatistica. Todas as variáveis analisadas apresentaram estrutura de dependência espacial, e ajustaram-se ao modelo exponencial. Nos semivariograma individuais o GDE foi classificado como fraco e moderado e os semivariograma escalonados o GDE foi classificado como moderado e forte. Os semivariograma escalonado apresentaram alcance maiores que o espaçamento da malha variando entre 17,59 a 30 m

Compact stars made of fermionic dark matter

Compact stars consisting of fermions with arbitrary masses and interaction strengths are studied by solving the structure equation of general relativity, the Tolman-Oppenheimer-Volkoff equations. Scaling solutions are derived for a free and an interacting Fermi gas and tested by numerical calculations. We demonstrate that there is a unique mass-radius relation for compact stars made of free fermions which is independent of the fermion mass. For sufficiently strong interactions, the maximum stable mass of compact stars and its radius are controlled by the parameter of the interaction, both increasing linearly with the interaction strength. The mass-radius relation for compact stars made of strongly interacting fermions shows that the radius remains approximately constant for a wide range of compact star masses.Comment: 19 pages, 8 figures, refs. added, version to appear in Physical Review

Reaction rates and transport in neutron stars

Understanding signals from neutron stars requires knowledge about the transport inside the star. We review the transport properties and the underlying reaction rates of dense hadronic and quark matter in the crust and the core of neutron stars and point out open problems and future directions.Comment: 74 pages; commissioned for the book "Physics and Astrophysics of Neutron Stars", NewCompStar COST Action MP1304; version 3: minor changes, references updated, overview graphic added in the introduction, improvements in Sec IV.A.

Non-Linear Axion Dynamics and Formation of Cosmological Pseudo-Solitons

The $(3+1)$-dimensional evolution of an inhomogeneous axion field configuration around the QCD epoch is studied numerically, including important non-linear effects due to the attractive self-interaction. It is found that axion perturbations on scales corresponding to causally disconnected regions at $T \sim 1 \, {\rm GeV}$ can lead to very dense pseudo-soliton configurations we call axitons. These configurations evolve to axion miniclusters with present density \rho_a \ga 10^{-8}\,{\rm g \, cm^{-3}}. This is high enough for the collisional $2a \rightarrow 2a$ process to lead to Bose--Einstein relaxation in the gravitationally bound clumps of axions, forming Bose stars.Comment: 27 pages plus 13 figures (upon request: [email protected]), LaTeX, FNAL--PUB--93/335--