Pulsar kicks from neutrino oscillations

Neutrino oscillations in a core-collapse supernova may be responsible for the observed rapid motions of pulsars. Given the present bounds on the neutrino masses, the pulsar kicks require a sterile neutrino with mass 2-20 keV and a small mixing with active neutrinos. The same particle can be the cosmological dark matter. Its existence can be confirmed the by the X-ray telescopes if they detect a 1-10 keV photon line from the decays of the relic sterile neutrinos. In addition, one may be able to detect gravity waves from a pulsar being accelerated by neutrinos in the event of a nearby supernova.Comment: invited review article to appear in Int. J. Mod. Phys. (21 pages, 6 figures

The JBEI quantitative metabolic modeling library (jQMM): a python library for modeling microbial metabolism

Modeling of microbial metabolism is a topic of growing importance in biotechnology. Mathematical modeling helps provide a mechanistic understanding for the studied process, separating the main drivers from the circumstantial ones, bounding the outcomes of experiments and guiding engineering approaches. Among different modeling schemes, the quantification of intracellular metabolic fluxes (i.e. the rate of each reaction in cellular metabolism) is of particular interest for metabolic engineering because it describes how carbon and energy flow throughout the cell. In addition to flux analysis, new methods for the effective use of the ever more readily available and abundant -omics data (i.e. transcriptomics, proteomics and metabolomics) are urgently needed

Status of Schottky Diagnostics in the ANKA Storage Ring

The status of longitudinal and transverse Schottky observation systems for the synchrotron light source ANKA is presented. ANKA regularly operates in a dedicated low alpha mode with short bunches for the generation of coherent THz radiation. The Schottky measurement results are shown and compared with theoretical predictions for the regular as well as the different stages of the low alpha mode of operation. Special care had to be taken to control and mitigate the impact from strong coherent lines of the short bunches on the signal processing chain. The system setup is shown, expected and unexpected observations as well as applications are discussed

Natural Quintessence with Gauge Coupling Unification

We show that a positive accelerating universe can be obtained simply by the dynamics of a non-abelian gauge group. It is the condensates of the chiral fields that obtain a negative power potential, below the condensation scale, and allow for a quintessence interpretation of these fields. The only free parameters in this model are $N_c$ and $N_f$ and the number of dynamically gauge singlet bilinear fields $\phi$ generated below the condensation scale. We show that it is possible to have unification of all coupling constants, including the standard and non standard model couplings, while having an acceptable phenomenology of $\phi$ as the cosmological constant. This is done without any fine tuning of the initial conditions. The problem of coincidence (why the universe has only recently started an accelerating period) is not solved but it is put at the same level as what the particle content of the standard model is.Comment: minor changes(discussion on field normalization included), reference added, accepted in Phy.Rev.Lett., 5 pages,LateX,2 Figure

Pulsar Kicks and Spin Tilts in the Close Double Neutron Stars PSR J0737-3039, PSR B1534+12 and PSR B1913+16

In view of the recent measurement of the scintillation velocity for PSR J0737-3039, we examine the complete set of constraints imposed on the pulsar B natal kicks (magnitude and orientation) and predict the most favorable pulsar kick velocity and spin tilt for both isotropic and polar kicks. Our analysis takes into account both currently unknown parameters: the orientation of the orbital plane on the sky (Omega) and the radial component of the systemic velocity (V_r). Assuming that the system's peculiar velocity is entirely due to the second supernova explosion, we find that the system may have crossed the Galactic plane multiple times since the birth of the second neutron star and that the post-supernova peculiar velocity could have been as high as 1200km/s. We also confirm the absolute lower and upper limits on the physical parameters derived in our earlier study. For specific combinations of the two unknown parameters Omega and V_r, however, we find much tighter constraints on the pre-supernova binary configuration and natal kicks imparted to pulsar B, as well as on the age of system. Once Omega is measured in the coming year, it will be straightforward to use the results presented here to further constrain the natal kicks and the spin-tilt predictions. We complete our comprehensive study and derive similar constraints and spin-tilt predictions for PSR B1534+12, where the only free parameter is V_r. Lastly, for PSR B1913+16, we update the progenitor and kick constraints using the measured pulsar spin tilt and allowing for Roche-lobe overflow from the progenitor of the pulsar companion.Comment: Replaced Fig. 16 with corrected version. See ApJ 616, p. 414 for high-resolution figures and notes added in proo

Quintessence Restrictions on Negative Power and Condensate Potentials

We study the cosmological evolution of scalar fields that arise from a phase transition at some energy scale \Lm_c. We focus on negative power potentials given by V=c\Lm_c^{4+n}\phi^{-n} and restrict the cosmological viable values of \Lm_c and $n$. We make a complete analysis of $V$ and impose $SN1a$ conditions on the different cosmological parameters. The cosmological observations ruled out models where the scalar field has reached its attractor solution. For models where this is not the case, the analytic approximated solutions are not good enough to determine whether a specific model is phenomenologically viable or not and the full differential equations must be numerically solved. The results are not fine tuned since a change of 45% on the initial conditions does not spoil the final results. We also determine the values of $N_c, N_f$ that give a condensation scale \Lm_c consistent with gauge coupling unification, leaving only four models that satisfy unification and SN1a constraints.Comment: 15 pages, LaTeX, 8 Figures. Minor changes in text, a discussion on initial conditions added (accepted in Phys.Rev.D

Ultra High Energy Cosmic Rays and Inflation Relics

There are two processes of matter creation after inflation that may be relevant to the resolution of the puzzle of cosmic rays observed with energies beyond GZK cut-off: 1) gravitational creation of superheavy (quasi)stable particles, and 2) non-thermal phase transitions leading to formation of topological defects. We review both possibilities.Comment: Submitted to Physics Report

Measuring High Energy Neutrino-Nucleon Cross Sections With Future Neutrino Telescopes

Next generation kilometer-scale neutrino telescopes, such as ICECUBE, can test standard model predictions for neutrino-nucleon cross sections at energies well beyond the reach of collider experiments. At energies near a PeV and higher, the Earth becomes opaque to neutrinos. At these energies, the ratio of upgoing and downgoing events can be used to measure the total neutrino-nucleon cross section given the presence of an adequate high energy neutrino flux.Comment: 4 pages, 5 figure