Notes on the Breeding of Tropidopria Conica Fabr

n/

BOOMERanG Data Suggest a Purely Baryonic Universe

The amplitudes of peaks in the angular power spectrum of anisotropies in the microwave background radiation depend on the mass content of the universe. The second peak should be prominent when cold dark matter is dominant, but is depressed when baryons dominate. Recent microwave background data are consistent with a purely baryonic universe with Omega(matter) = Omega(baryon) ~ 0.03 and Omega(Lambda) ~ 1.Comment: 10 pages AASTeX with 1 color postscript figure. Accepted for publication in ApJ Letters. And yes, the prediction was in the literature before the dat

Is dark matter an extra-dimensional effect?

We investigate the possibility that the observed behavior of test particles outside galaxies, which is usually explained by assuming the presence of dark matter, is the result of the dynamical evolution of particles in higher dimensional space-times. Hence, dark matter may be a direct consequence of the presence of an extra force, generated by the presence of extra-dimensions, which modifies the dynamic law of motion, but does not change the intrinsic properties of the particles, like, for example, the mass (inertia). We discuss in some detail several possible particular forms for the extra force, and the acceleration law of the particles is derived. Therefore, the constancy of the galactic rotation curves may be considered as an empirical evidence for the existence of the extra dimensions.Comment: 11 pages, no figures, accepted for publication in MPLA; references adde

Magnetic Fields in the Center of the Perseus Cluster

We present Very Long Baseline Array (VLBA) observations of the nucleus of NGC 1275, the central, dominant galaxy in the Perseus cluster of galaxies. These are the first observations to resolve the linearly polarized emission from 3C84, and from them we determine a Faraday rotation measure (RM) ranging from 6500 to 7500 rad/m^2 across the tip of the bright southern jet component. At 22 GHz some polarization is also detected from the central parsec of 3C84, indicating the presence of even more extreme RMs that depolarize the core at lower frequencies. The nature of the Faraday screen is most consistent with being produced by magnetic fields associated with the optical filaments of ionized gas in the Perseus Cluster.Comment: Accepted for publication in MNRA

Occurrence of normal and anomalous diffusion in polygonal billiard channels

From extensive numerical simulations, we find that periodic polygonal billiard channels with angles which are irrational multiples of pi generically exhibit normal diffusion (linear growth of the mean squared displacement) when they have a finite horizon, i.e. when no particle can travel arbitrarily far without colliding. For the infinite horizon case we present numerical tests showing that the mean squared displacement instead grows asymptotically as t log t. When the unit cell contains accessible parallel scatterers, however, we always find anomalous super-diffusion, i.e. power-law growth with an exponent larger than 1. This behavior cannot be accounted for quantitatively by a simple continuous-time random walk model. Instead, we argue that anomalous diffusion correlates with the existence of families of propagating periodic orbits. Finally we show that when a configuration with parallel scatterers is approached there is a crossover from normal to anomalous diffusion, with the diffusion coefficient exhibiting a power-law divergence.Comment: 9 pages, 15 figures. Revised after referee reports: redrawn figures, additional comments. Some higher quality figures available at http://www.fis.unam.mx/~dsander

The luminosity function of the brightest galaxies in the IRAS survey

Results from a study of the far infrared properties of the brightest galaxies in the IRAS survey are described. There is a correlation between the infrared luminosity and the infrared to optical luminosity ratio and between the infrared luminosity and the far infrared color temperature in these galaxies. The infrared bright galaxies represent a significant component of extragalactic objects in the local universe, being comparable in space density to the Seyferts, optically identified starburst galaxies, and more numerous than quasars at the same bolometric luminosity. The far infrared luminosity in the local universe is approximately 25% of the starlight output in the same volume

Unified entropy, entanglement measures and monogamy of multi-party entanglement

We show that restricted shareability of multi-qubit entanglement can be fully characterized by unified-$(q,s)$ entropy. We provide a two-parameter class of bipartite entanglement measures, namely unified-$(q,s)$ entanglement with its analytic formula in two-qubit systems for $q\geq 1$, $0\leq s \leq1$ and $qs\leq3$. Using unified-$(q,s)$ entanglement, we establish a broad class of the monogamy inequalities of multi-qubit entanglement for $q\geq2$, $0\leq s \leq1$ and $qs\leq3$.Comment: 17 pages, 1 figur