Investigation of line-of-sight propagation in dense atmosphere, phase 3, part 1

The investigation of microwave absorption in the 1 to 10 GHz frequency band by the Jovian atmosphere has continued, and an estimate of the strength of signal fading at these frequencies due to layers of turbulence in Jupiter's atmosphere is given. The microwave absorption due to gaseous ammonia is estimated both in terms of a power loss in dB/km, and in total power loss in dB for slant-path communication with a probe at altitudes down to pressures of several tens of atmospheres. The graphs indicate a frequency-squared scaling of the absorption, and appreciable losses at altitudes where the pressure is several atmospheres. An estimate of turbulence strength is given. This may turn out to be quite crude considering the absence of any relevant data. A planetary scaling law which appears to hold reasonably well for Earth to Venus, is extrapolated to Jupiter. No reasonable modifications of the estimate can alter the conclusion that direct-path fading is negligible for pressure regimes up to 20 atm

Advanced Moisture and Temperature Sounder (AMTS) study

Retrieval of tropospheric humidity profiles from satellite-based upwelling radiances are shown to be improved by using physical methods for obtaining first-guess profiles as well as for inverting the radiative transfer equation by relaxation. The first guess is based on an empirically verified hypothesis, from theoretical considerations, that the brightness temperature corresponding to the radiance should be approximately equal to the actual temperatue at a channel-invariant optical depth provided that the surface and stratospheric contributions to the radiance are small. Even greater improvement of retrieved humidity profiles can be accomplished by increasing the number of channels used and by selecting their spectral location and bandpass to obtain sharper independent weighting functions. For example, the AMTS system, with high resolution water channels at 1650, 1700, 1839, 1850 and 1930 cm, is shown to be capable of reducing the retrieved water vapor errors in 200 mb thick layers by a factor of two or three relative to the HIRS-2 system errors. Expected AMTS errors in tropical layer water content are particularly low, less than 20% at all levels, and of the order of 10% or less in the middle troposphere

Progress in Electroweak Baryogenesis

Recent work on generating the excess of matter over antimatter in the early universe during the electroweak phase transition is reviewed.Comment: 50 pages (figures on request), uses harvmac (table of contents correct for "l" format), UCSD-93-2,BU-HEP-93-

An alternative to the plasma emission model: Particle-In-Cell, self-consistent electromagnetic wave emission simulations of solar type III radio bursts

1.5D PIC, relativistic, fully electromagnetic (EM) simulations are used to model EM wave emission generation in the context of solar type III radio bursts. The model studies generation of EM waves by a super-thermal, hot beam of electrons injected into a plasma thread that contains uniform longitudinal magnetic field and a parabolic density gradient. In effect, a single magnetic line connecting Sun to earth is considered, for which several cases are studied. (i) We find that the physical system without a beam is stable and only low amplitude level EM drift waves (noise) are excited. (ii) The beam injection direction is controlled by setting either longitudinal or oblique electron initial drift speed, i.e. by setting the beam pitch angle. In the case of zero pitch angle, the beam excites only electrostatic, standing waves, oscillating at plasma frequency, in the beam injection spatial location, and only low level EM drift wave noise is also generated. (iii) In the case of oblique beam pitch angles, again electrostatic waves with same properties are excited. However, now the beam also generates EM waves with the properties commensurate to type III radio bursts. The latter is evidenced by the wavelet analysis of transverse electric field component, which shows that as the beam moves to the regions of lower density, frequency of the EM waves drops accordingly. (iv) When the density gradient is removed, electron beam with an oblique pitch angle still generates the EM radiation. However, in the latter case no frequency decrease is seen. Within the limitations of the model, the study presents the first attempt to produce simulated dynamical spectrum of type III radio bursts in fully kinetic plasma model. The latter is based on 1.5D non-zero pitch angle (non-gyrotropic) electron beam, that is an alternative to the plasma emission classical mechanism.Comment: Physics of Plasmas, in press, May 2011 issue (final accepted version

Charged and superconducting vortices in dense quark matter

Quark matter at astrophysical densities may contain stable vortices due to the spontaneous breaking of hypercharge symmetry by kaon condensation. We argue that these vortices could be both charged and electrically superconducting. Current carrying loops (vortons) could be long lived and play a role in the magnetic and transport properties of this matter. We provide a scenario for vorton formation in protoneutron stars.Comment: Replaced with the published version. A typographical error in Eq. 2 is correcte

Gauge/Anomaly Syzygy and Generalized Brane World Models of Supersymmetry Breaking

In theories in which SUSY is broken on a brane separated from the MSSM matter fields, supersymmetry breaking is naturally mediated in a variety of ways. Absent other light fields in the theory, gravity will mediate supersymmetry breaking through the conformal anomaly. If gauge fields propagate in the extra dimension they, too, can mediate supersymmetry breaking effects. The presence of gauge fields in the bulk motivates us to consider the effects of new messenger fields with holomorphic and non-holomorphic couplings to the supersymmetry breaking sector. These can lead to contributions to the soft masses of MSSM fields which dramatically alter the features of brane world scenarios of supersymmetry breaking. In particular, they can solve the negative slepton mass squared problem of anomaly mediation and change the predictions of gaugino mediation.Comment: 4 pages, RevTe

Renormalization schemes and the range of two-nucleon effective field theory

The OS and PDS renormalization schemes for the effective field theory with nucleons and pions are investigated. We explain in detail how the renormalization is implemented using local counterterms. Fits to the NN scattering data are performed in the 1S0 and 3S1 channels for different values of mu_R. An error analysis indicates that the range of the theory with perturbative pions is consistent with 500 MeV.Comment: 40 pages, typos corrected, journal version. Discussion of the range in section VII clarified, conclusions unchange

A Project Based Approach to Statistics and Data Science

In an increasingly data-driven world, facility with statistics is more important than ever for our students. At institutions without a statistician, it often falls to the mathematics faculty to teach statistics courses. This paper presents a model that a mathematician asked to teach statistics can follow. This model entails connecting with faculty from numerous departments on campus to develop a list of topics, building a repository of real-world datasets from these faculty, and creating projects where students interface with these datasets to write lab reports aimed at consumers of statistics in other disciplines. The end result is students who are well prepared for interdisciplinary research, who are accustomed to coping with the idiosyncrasies of real data, and who have sharpened their technical writing and speaking skills