A unified solution to the small scale problems of the Lambda CDM model II: introducing parent-satellite interaction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Flattening of the resonance spectrum of hadrons from κ-deformed Poincaré algebra

Recently Lukierski et al. [1] defined a κ-deformed Poincaré algebra which is characterized by having the energy-momentum and angular momentum sub-algebras not deformed. Further Biedenharn et al. [2] showed that on gauging the κ-deformed electron with the electromagnetic field, one can set a limit on the allowed value of the deformation parameter ∈ ≡ 1/κ < 1 fm. We show that one gets Regge like angular excitations, J, of the mesons, non-strange and strange baryons, with a value of ∈ ∼ 0.082 fm and predict a flattening with J of the corresponding trajectories. The Regge fit improves on including deformation, particularly for the baryon spectrum.

Evaluation of effective nucleon-nucleon potential and description of α-cluster type nuclei in restricted dynamics approach

The application of the Restricted Dynamics Approach in nuclear theory, based on the approximate solution of many-particle Schrödinger equation, which accounts for all conservation laws in many-nucleon system, is discussed. The Strictly Restricted Dynamics Model is used for the evaluation of binding energies, level schemes, E2 and Ml transition probabilities as well as the electric quadrupole and magnetic dipole momenta of light a-cluster type nuclei in the region 4 ≤ A ≤ 40. The parameters of effective nucleonnucleon interaction potential are evaluated from the ground state binding energies of doubly magic nuclei 4He, 16O and 40Ca.

A simple relativistic model of p(p)over-bar-]K+K-

We compare a model calculation with some available experimental data (LEAP 92) on KK̄ production. We believe the simplicity of the model makes it a useful tool for studying charm and beauty baryon production, for which also experimental data will soon be profuse.

Fatores associados ao metabolismo energetico na obesidade

Obesity is fundamentally a problem of energy balance that develops when the energy intake is greater than the total energy expenditure (TEE). TEE is composed by the sum of resting energy expenditure (REE), thermal effect of foods and thermal effect of physical activity. Many factors can affect energy expenditure and energy homeostasis. Historically, the energy expenditure has been measured by indirect calorimetry. However, more recently, the use of doubly labeled water has allowed the assessment of energy expenditure in a 24 hour period, which expanded the knowledge on energy metabolism. Factors such as gender, age, thyroid disorders, physical activity and body composition affect REE as already established in the literature. However, there has been speculation whether other factors, such as adipocytokines and diet composition, which might be involved in the genesis of obesity by decreasing the REE. So, this paper aims to review the factors that can alter the energy metabolism.

Constraining H-0 in general dark energy models from Sunyaev-Zeldovich/X-ray technique and complementary probes

In accelerating dark energy models, the estimates of the Hubble constant, Ho, from Sunyaev-Zerdovich effect (SZE) and X-ray surface brightness of galaxy clusters may depend on the matter content (Omega(M)), the curvature (Omega(K)) and the equation of state parameter GO. In this article, by using a sample of 25 angular diameter distances of galaxy clusters described by the elliptical beta model obtained through the SZE/X-ray technique, we constrain Ho in the framework of a general ACDM model (arbitrary curvature) and a flat XCDM model with a constant equation of state parameter omega = p(x)/rho(x). In order to avoid the use of priors in the cosmological parameters, we apply a joint analysis involving the baryon acoustic oscillations (BA()) and the (MB Shift Parameter signature. By taking into account the statistical and systematic errors of the SZE/X-ray technique we obtain for nonflat ACDM model H-0 = 74(-4.0)(+5.0) km s(-1) Mpc(-1) (1 sigma) whereas for a fiat universe with constant equation of state parameter we find H-0 = 72(-4.0)(+5.5) km s(-1) Mpc(-1)(1 sigma). By assuming that galaxy clusters are described by a spherical beta model these results change to H-0 = 6(-7.0)(+8.0) and H-0 = 59(-6.0)(+9.0) km s(-1) Mpc(-1)(1 sigma), respectively. The results from elliptical description are in good agreement with independent studies from the Hubble Space Telescope key project and recent estimates based on the Wilkinson Microwave Anisotropy Probe, thereby suggesting that the combination of these three independent phenomena provides an interesting method to constrain the Bubble constant. As an extra bonus, the adoption of the elliptical description is revealed to be a quite realistic assumption. Finally, by comparing these results with a recent determination for a, flat ACDM model using only the SZE/X-ray technique and BAO, we see that the geometry has a very weak influence on H-0 estimates for this combination of data.

DIFFERENTIAL INVOLVEMENT OF DORSAL RAPHE SUBNUCLEI IN THE REGULATION OF ANXIETY- AND PANIC-RELATED DEFENSIVE BEHAVIORS

A wealth of evidence indicates that the dorsal raphe nucleus (DR) is not a homogenous structure, but an aggregate of distinctive populations of neurons that may differ anatomically, neurochemically and functionally. Other findings suggest that serotonergic neurons within the mid-caudal and caudal part of the DR are involved in anxiety processing while those within the lateral wings (IwDR) and ventrolateral periaqueductal gray (vIPAG) are responsive to panic-evoking stimuli/situations. However, no study to date has directly compared the activity of 5-HT and non-5HT neurons within different subnuclei of the DR following the expression of anxiety- and panic-related defensive responses. In the present investigation, the number of doubly immunostained cells for Fos protein and tryptophan hydroxylase, a marker of serotonergic neurons, was assessed within the rat DR, median raphe nucleus (MRN) and PAG following inhibitory avoidance and escape performance in the elevated T-maze, behaviors associated with anxiety and panic, respectively. Inhibitory avoidance, but not escape, significantly increased the number of Fos-expressing serotonergic neurons within the mid-caudal part of the dorsal subnucleus, caudal and interfascicular subnuclei of the DR and in the MRN. Escape, on the other hand, caused a marked increase in the activity of non-5HT cells within the IwDR, vIPAG, dorsolateral and dorsomedial columns of the PAG. These results strongly corroborate the view that different subsets of neurons in the DR are activated by anxiety- and panic-relevant stimuli/situations, with important implications for the understanding of the pathophysiology of generalized anxiety and panic disorders. (C) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

New cosmic accelerating scenario without dark energy

We propose an alternative, nonsingular, cosmic scenario based on gravitationally induced particle production. The model is an attempt to evade the coincidence and cosmological constant problems of the standard model (Lambda CDM) and also to connect the early and late time accelerating stages of the Universe. Our space-time emerges from a pure initial de Sitter stage thereby providing a natural solution to the horizon problem. Subsequently, due to an instability provoked by the production of massless particles, the Universe evolves smoothly to the standard radiation dominated era thereby ending the production of radiation as required by the conformal invariance. Next, the radiation becomes subdominant with the Universe entering in the cold dark matter dominated era. Finally, the negative pressure associated with the creation of cold dark matter (CCDM model) particles accelerates the expansion and drives the Universe to a final de Sitter stage. The late time cosmic expansion history of the CCDM model is exactly like in the standard Lambda CDM model; however, there is no dark energy. The model evolves between two limiting (early and late time) de Sitter regimes. All the stages are also discussed in terms of a scalar field description. This complete scenario is fully determined by two extreme energy densities, or equivalently, the associated de Sitter Hubble scales connected by rho(I)/rho(f) = (H-I/H-f)(2) similar to 10(122), a result that has no correlation with the cosmological constant problem. We also study the linear growth of matter perturbations at the final accelerating stage. It is found that the CCDM growth index can be written as a function of the Lambda growth index, gamma(Lambda) similar or equal to 6/11. In this framework, we also compare the observed growth rate of clustering with that predicted by the current CCDM model. Performing a chi(2) statistical test we show that the CCDM model provides growth rates that match sufficiently well with the observed growth rate of structure.

Scalar field description for parametric models of dark energy

We investigate theoretical and observational aspects of a time-dependent parameterization for the dark energy equation of state w(z), which is a well behaved function of the redshift z over the entire cosmological evolution, i.e., z is an element of [-1, infinity). By using a theoretical algorithm of constructing the quintes-sence potential directly from the w(z) function, we derive and discuss the general features of the resulting potential for the cases in which dark energy is separately conserved and when it is coupled to dark matter. Since the parameterization here discussed allows us to divide the parametric plane in defined regions associated to distinct classes of dark energy models, we use some of the most recent observations from type Ia supernovae, baryon acoustic oscillation peak and Cosmic Microwave Background shift parameter to check which class is observationally preferred. We show that the largest portion of the confidence contours lies into the region corresponding to a possible crossing of the so-called phantom divide line at some point of the cosmic evolution.

The full Fisher matrix for galaxy surveys

Starting from the Fisher matrix for counts in cells, we derive the full Fisher matrix for surveys of multiple tracers of large-scale structure. The key step is the classical approximation, which allows us to write the inverse of the covariance of the galaxy counts in terms of the naive matrix inverse of the covariance in a mixed position-space and Fourier-space basis. We then compute the Fisher matrix for the power spectrum in bins of the 3D wavenumber , the Fisher matrix for functions of position (or redshift z) such as the linear bias of the tracers and/or the growth function and the cross-terms of the Fisher matrix that expresses the correlations between estimations of the power spectrum and estimations of the bias. When the bias and growth function are fully specified, and the Fourier-space bins are large enough that the covariance between them can be neglected, the Fisher matrix for the power spectrum reduces to the widely used result that was first derived by Feldman, Kaiser & Peacock. Assuming isotropy, a fully analytical calculation of the Fisher matrix in the classical approximation can be performed in the case of a constant-density, volume-limited survey.

Application of the log-conformation tensor to three-dimensional time-dependent free surface flows

The numerical simulation of flows of highly elastic fluids has been the subject of intense research over the past decades with important industrial applications. Therefore, many efforts have been made to improve the convergence capabilities of the numerical methods employed to simulate viscoelastic fluid flows. An important contribution for the solution of the High-Weissenberg Number Problem has been presented by Fattal and Kupferman [J. Non-Newton. Fluid. Mech. 123 (2004) 281-285] who developed the matrix-logarithm of the conformation tensor technique, henceforth called log-conformation tensor. Its advantage is a better approximation of the large growth of the stress tensor that occur in some regions of the flow and it is doubly beneficial in that it ensures physically correct stress fields, allowing converged computations at high Weissenberg number flows. In this work we investigate the application of the log-conformation tensor to three-dimensional unsteady free surface flows. The log-conformation tensor formulation was applied to solve the Upper-Convected Maxwell (UCM) constitutive equation while the momentum equation was solved using a finite difference Marker-and-Cell type method. The resulting developed code is validated by comparing the log-conformation results with the analytic solution for fully developed pipe flows. To illustrate the stability of the log-conformation tensor approach in solving three-dimensional free surface flows, results from the simulation of the extrudate swell and jet buckling phenomena of UCM fluids at high Weissenberg numbers are presented. (C) 2012 Elsevier B.V. All rights reserved.

Measurements of D-0 and D* production in p plus p collisions at root s=200 GeV

We report measurements of charmed-hadron (D-0, D*) production cross sections at midrapidity in p + p collisions at a center-of-mass energy of 200 GeV by the STAR experiment. Charmed hadrons were reconstructed via the hadronic decays D-0 -> K- pi(+), D*(+) -> D-0 pi(+) -> K-pi(+)pi(+) and their charge conjugates, covering the p(T) range of 0.6-2.0 and 2.0-6.0 GeV/c for D-0 and D*(+), respectively. From this analysis, the charm-pair production cross section at midrapidity is d sigma/dy vertical bar(c (c) over bar)(y-0) = 170+/-45(stat)(-59)(+38()sys) mu b. The extracted charm-pair cross section is compared to perturbative QCD calculations. The transverse momentum differential cross section is found to be consistent with the upper bound of a fixed-order next-to-leading logarithm calculation.

1(--) and 0(++) heavy four-quark and molecule states in QCD

We estimate the masses of the 1(--) heavy four-quark and molecule states by combining exponential Laplace (LSR) and finite energy (FESR) sum rules known perturbatively to lowest order (LO) in alpha(s) but including non-perturbative terms up to the complete dimension-six condensate contributions. This approach allows to fix more precisely the value of the QCD continuum threshold (often taken ad hoc) at which the optimal result is extracted. We use double ratio of sum rules (DRSR) for determining the SU(3) breakings terms. We also study the effects of the heavy quark mass definitions on these LO results. The SU(3) mass-splittings of about (50-110) MeV and the ones of about (250-300) MeV between the lowest ground states and their 1st radial excitations are (almost) heavy-flavor independent. The mass predictions summarized in Table 4 are compared with the ones in the literature (when available) and with the three Y-c(4260, 4360, 4660) and Y-b(10890) 1(--) experimental candidates. We conclude (to this order approximation) that the lowest observed state cannot be a pure 1(--) four-quark nor a pure molecule but may result from their mixings. We extend the above analyzes to the 0(++) four-quark and molecule states which are about (0.5-1) GeV heavier than the corresponding 1(--) states, while the splittings between the 0(++) lowest ground state and the 1st radial excitation is about (300-500) MeV. We complete the analysis by estimating the decay constants of the 1(--) and 0(++) four-quark states which are tiny and which exhibit a 1/M-Q behavior. Our predictions can be further tested using some alternative non-perturbative approaches or/and at LHCb and some other hadron factories. (c) 2012 Elsevier B.V. All rights reserved.

Self-bound interacting QCD matter in compact stars

The quark gluon plasma (QGP) at zero temperature and high baryon number is a system that may be present inside compact stars. It is quite possible that this cold QGP shares some relevant features with the hot QGP observed in heavy ion collisions, being also a strongly interacting system. In a previous work we have derived from the QCD Lagrangian an equation of state (EOS) for the cold QGP, which can be considered an improved version of the MIT bag-model EOS. Compared to the latter, our EOS reaches higher values of the pressure at comparable baryon densities. This feature is due to perturbative corrections and also to nonperturbative effects. Here we apply this EOS to the study of neutron stars, discussing the absolute stability of quark matter and computing the mass-radius relation for self-bound (strange) stars. The maximum masses of the sequences exceed two solar masses, in agreement with the recently measured values of the mass of the pulsar PSR J1614-2230, and the corresponding radii of around 10-11 km.

The infrared fundamental intensities of some cyanopolyynes

Some cyanopolyynes, HCnN (n = 1, 3, ... , 17), are investigated by means of calculations at the MP2/cc-pVTZ and CCSD/cc-pVDZ levels. Although the MP2/cc-pVTZ results for geometries and molecular dipole moments are encouraging, the CCSD/cc-pVDZ level was superior for the study of infrared fundamental intensities. The main bands are also analyzed with a charge-charge flux-dipole flux (CCFDF) partition model based on quantities given by the Quantum Theory of Atoms in Molecules (QTAIM). The intensity of vibrations corresponding to the stretching of CH bonds (3471-3473 cm(-1)) increases in line with the number of carbon atoms (from 61 to 146 km mol(-1) between HCN and HC13N). This increase is due to the charge flux contribution while the other contributions remain roughly unaltered except for HCN. Moreover, the hydrogen atom loses an almost constant amount of electronic charge during the CH bond enlargement and a small fraction of this charge spreads to atoms farther and farther away from hydrogen as the molecule size increases. The band associated with the doubly degenerate CH bending vibrations (643-732 cm(-1)) presents approximately the same intensity in all the studied cyanopolyynes (from 67 to 76 km mol(-1)). The CCFDF/QTAIM contributions are also nearly the same for these bending modes in HC5N and larger systems. The intensity of the mode mostly identified as CN stretching (around 2378-2399 cm(-1) except for HCN) increases from HCN up to HC7N (from 0.3 to 83 km mol(-1)) and nearly stabilizes around 80-90 km mol(-1) for larger systems. The CCFDF/QTAIM contributions for this mode also change significantly up to HC7N and remain almost constant in larger systems. We also observed the appearing of a very relevant band between 2283 and 2342 cm(-1). This mode is mainly associated with the symmetric stretching of CC triple bonds near the molecule center and exhibits large charge fluxes while the other contributions are almost negligible in the largest cyanopolyynes. The two vibrational bands associated with the smallest frequencies are also studied and extrapolation equations are suggested to predict their positions in larger cyanopolyynes. (C) 2012 Elsevier B.V. All rights reserved.