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Physical Sciences and Mathematics Commons

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Loyola Marymount University and Loyola Law School

Series

2002

Articles 1 - 5 of 5

Full-Text Articles in Physical Sciences and Mathematics

Quiet Time Variability Of The Geosynchronous Magnetic Field And Its Response To The Solar Wind, Jeff Sanny, J. A. Tapia, D. G. Sibeck, M. B. Moldwin Dec 2002

Quiet Time Variability Of The Geosynchronous Magnetic Field And Its Response To The Solar Wind, Jeff Sanny, J. A. Tapia, D. G. Sibeck, M. B. Moldwin

Physics Faculty Works

We present a survey of the variability of the geosynchronous magnetic field strength on the dayside using observations by the GOES satellites over a period exceeding 4 years. Only intervals of reduced geomagnetic activity, as defined by Dst > −20 nT, were considered in this study. The magnetic field strength data were filtered with a passband of 1.7 mHz to 17 mHz (1–10 minutes), a process that eliminates the diurnal variation of the field strength and the effects of most of the higher frequency (>17 mHz) ultralow-frequency (ULF) waves. The geosynchronous field strength appears to exhibit the greatest variability in …


Cosmic Rays Above The Ankle From Z Bursts, Gabriele U. Varieschi Jan 2002

Cosmic Rays Above The Ankle From Z Bursts, Gabriele U. Varieschi

Physics Faculty Works

Neutrinos from far away sources annihilating at the Z resonance on relic neutrinos may give origin to the ultrahigh-energy cosmic rays. Here we present predictions of this mechanism with relic neutrinos lighter than 1 eV, which do not gravitationally cluster. We show that not only the super GZK events, but the "ankle" and all events above it can be accounted for. Most primaries above the ankle are predicted to be nucleons up to $10^{20.0}$ eV and photons at higher energies. We also find an accumulation at the GZK cutoff energy, a hint of which can be seen in the data.


An Effective Version Of Belyi's Theorem, Lily S. Khadjavi Jan 2002

An Effective Version Of Belyi's Theorem, Lily S. Khadjavi

Mathematics Faculty Works

We compute bounds on covering maps that arise in Belyi's Theorem. In particular, we construct a library of height properties and then apply it to algorithms that produce Belyi maps. Such maps are used to give coverings from algebraic curves to the projective line ramified over at most three points. The computations here give upper bounds on the degree and coefficients of polynomials and rational functions over the rationals that send a given set of algebraic numbers to the set {0,1,∞} with the additional property that the only critical values are also contained in {0,1,∞}.


Ideal Theory In Prüfer Domains - An Unconventional Approach, Edward Mosteig Jan 2002

Ideal Theory In Prüfer Domains - An Unconventional Approach, Edward Mosteig

Mathematics Faculty Works

In Prüfer domains of finite character, ideals are represented as finite intersections of special ideals which are proper generalizations of the classical primary ideals. We show that representations of ideals as shortest intersections of primal or quasi-primary ideals exist and are unique. Moreover, every non-zero ideal is the product of uniquely determined pairwise comaximal quasi-primary ideals. Semigroups of primal and quasi-primary ideals with fixed associated primes are also investigated in arbitrary Prüfer domains. Their structures can be described in terms of the value groups of localizations.


Valuations And Filtrations, Edward Mosteig Jan 2002

Valuations And Filtrations, Edward Mosteig

Mathematics Faculty Works

The classical theory of Gröbner bases, as developed by Bruno Buchberger, can be expanded to utilize objects more general than term orders. Each term order on the polynomial ring k[x] produces a filtration of k[x] and a valuation ring of the rational function field k(x). The algorithms developed by Buchberger can be performed by using directly the induced valuation or filtration in place of the term order. There are many valuations and filtrations that are suitable for this general computational framework that are not derived from term orders, even after a change of variables. Here we study how to translate …