Strangelet spectra from type II supernovae

We study in this work the fate of strangelets injected as a contamination in the tail of a "strange matter-driven" supernova shock. A simple model for the fragmentation and braking of the strangelets when they pass through the expanding oxygen shell is presented and solved to understand the reprocessing of this component. We find that the escaping spectrum is a scaled-down version of the one injected at the base of the oxygen shell. The supernova source is likely to produce low-energy particles of $A \sim 100-1000$ quite independently of the initial conditions. However, it is difficult that ultrarrelativistic strangelets (such as the hypothetical Centauro primaries) can have an origin in those explosive events.Comment: RevTex file, 5 pp., no figure

Decay versus survival of a localized state subjected to harmonic forcing: exact results

We investigate the survival probability of a localized 1-d quantum particle subjected to a time dependent potential of the form $rU(x)\sin{\omega t}$ with $U(x)=2\delta (x-a)$ or $U(x)= 2\delta(x-a)-2\delta (x+a)$. The particle is initially in a bound state produced by the binding potential $-2\delta (x)$. We prove that this probability goes to zero as $t\to\infty$ for almost all values of $r$, $\omega$, and $a$. The decay is initially exponential followed by a $t^{-3}$ law if $\omega$ is not close to resonances and $r$ is small; otherwise the exponential disappears and Fermi's golden rule fails. For exceptional sets of parameters $r,\omega$ and $a$ the survival probability never decays to zero, corresponding to the Floquet operator having a bound state. We show similar behavior even in the absence of a binding potential: permitting a free particle to be trapped by harmonically oscillating delta function potential

5.7 The Input of Home Telemonitoring for the Treatment of Chronic Heart Failure in Old People at High Risk

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HYDRODYNAMICAL MODELS OF TYPE II-P SUPERNOVA LIGHT CURVES

RESUMEN Presentamos los progresos en el modelado de curvas de luz de supernovas de tipo II plateau (SNe II-P) obtenidos a partir de un código hidrodinámico unidimensional que recientemente hemos desarrollado. Usando modelos iniciales simples (polítropas) reprodujimos el comportamiento global de las curvas de luz observadas y analizamos la sensibilidad de la curva de luz a la variación de los parámetros libres. ABSTRACT We present progress in light curve models of type II-P supernovae (SNe II-P) obtained using a newly developed, one-dimensional hydrodynamic code. Using simple initial models (polytropes), we reproduced the global behavior of the observed light curves and we analyzed the sensitivity of the light curves to the variation of free parameters

Diffusive Ionization of Relativistic Hydrogen-Like Atom

Stochastic ionization of highly excited relativistic hydrogenlike atom in the monochromatic field is investigated. A theoretical analisis of chaotic dynamics of the relativistic electron based on Chirikov criterion is given for the cases of one- and three-dimensional atoms. Critical value of the external field is evaluated analitically. The diffusion coefficient and ionization time are calculated.Comment: 13 pages, latex, no figures, submitted to PR

The Fermi accelerator in atom optics

We study the classical and quantum dynamics of a Fermi accelerator realized by an atom bouncing off a modulated atomic mirror. We find that in a window of the modulation amplitude dynamical localization occurs in both position and momentum. A recent experiment [A. Steane, P. Szriftgiser, P. Desbiolles, and J. Dalibard, Phys. Rev. Lett. {\bf 74}, 4972 (1995)] shows that this system can be implemented experimentally.Comment: 5 pages, 5 figure

Structure of Strange Dwarfs with Color Superconducting Core

We study effects of two-flavor color superconductivity on the structure of strange dwarfs, which are stellar objects with similar masses and radii with ordinary white dwarfs but stabilized by the strange quark matter core. We find that unpaired quark matter is a good approximation to the core of strange dwarfs.Comment: 8 pages 5 figures, J. Phys. G, accepte

Hundred photon microwave ionization of Rydberg atoms in a static electric field

We present analytical and numerical results for the microwave excitation of nonhydrogenic atoms in a static electric field when up to 1000 photons are required to ionize an atom. For small microwave fields, dynamical localization in photon number leads to exponentially small ionization while above quantum delocalization border ionization goes in a diffusive way. For alkali atoms in a static field the ionization border is much lower than in hydrogen due to internal chaos.Comment: revtex, 4 pages, 5 figure

Rotation And Magnetic Evolution Of Superconducting Strange Stars

Is pulsar make up of strange matter? The magnetic field decay of a pulsar may be able to give us an answer. Since Cooper pairing of quarks occurs inside a sufficiently cold strange star, the strange stellar core is superconducting. In order to compensate the effect of rotation, different superconducting species inside a rotating strange star try to set up different values of London fields. Thus, we have a frustrated system. Using Ginzburg-Landau formalism, I solved the problem of rotating a superconducting strange star: Instead of setting up a global London field, vortex bundles carrying localized magnetic fields are formed. Moreover, the number density of vortex bundles is directly proportional to the angular speed of the star. Since it is energetically favorable for the vortex bundles to pin to magnetic flux tubes, the rotational dynamics and magnetic evolution of a strange star are coupled together, leading to the magnetic flux expulsion as the star slows down. I investigate this effect numerically and find that the characteristic field decay time is much less than 20~Myr in all reasonable parameter region. On the other hand, the characteristic magnetic field decay time for pulsars is $\geq 20$~Myr. Thus, my finding cast doubt on the hypothesis that pulsars are strange stars.Comment: 42 pages (including 13 eps figures) in AASTex 4.0 style with AMSFont

Curvature energy effects on strange quark matter nucleation at finite density

We consider the effects of the curvature energy term on thermal strange quark matter nucleation in dense neutron matter. Lower bounds on the temperature at which this process can take place are given and compared to those without the curvature term.Comment: PlainTex, 6 pp., IAG-USP Rep.5