An extension of Kedlaya's algorithm for hyperelliptic curves

In this paper we describe a generalisation and adaptation of Kedlaya's algorithm for computing the zeta function of a hyperelliptic curve over a finite field of odd characteristic that the author used for the implementation of the algorithm in the Magma library. We generalise the algorithm to the case of an even degree model. We also analyse the adaptation of working with the $x^idx/y^3$ rather than the $x^idx/y$ differential basis. This basis has the computational advantage of always leading to an integral transformation matrix whereas the latter fails to in small genus cases. There are some theoretical subtleties that arise in the even degree case where the two differential bases actually lead to different redundant eigenvalues that must be discarded.Comment: v3: some minor changes and addition of a reference to a paper by Theo van den Bogaar

Generation of Warm Dense Plasma on Solar Panel Infrastructure in Exo-Atmospheric Conditions

The use of a weaponized thermo-nuclear device in exo-atmospheric conditions would be of great impact on the material integrity of orbiting satellite infrastructure. Particular damage would occur to the multi-layered, solar cell components of such satellites. The rapid absorption of X-ray radiation originating from a nuclear blast into these layers occurs over a picosecond time scale and leads to the generation of Warm Dense Plasma (WDP). While incredibly difficult and costly to replicate in a laboratory setting, a collection of computational techniques and software libraries may be utilized to simulate the intricate atomic and subatomic physics characteristics of such an event. Use of the Monte Carlo sampling method within the Geant4 software library allows for the energy deposition and power density profiles by X-rays into this system to be determined. By understanding and modeling the different factors which can affect the absorption of thermonuclear X-ray radiation, specifically, “cold –X-ray radiation,” in the energy range of approximately 1 to 1.5 keV, the molecular dynamics modeling of WDP generation and evolution can be performed using the LAMMPS code library. One aspect modeled and utilized within this software is the Planck blackbody spectrum of X-rays, assumed to be emitted by the detonation. Another such factor explored is the effect of primary and secondary particle backscattering within the active solar cell layer. Ultimately, it was determined that the primary and secondary particle backscattering of photons and electrons occurs at such a relatively low rate that its effect on the properties of the generated WDP is negligible. Once the energy deposition and power density profiles are determined, LAMMPS is utilized in order to understand the spatio-temporal evolution of the WDP as well as the temperature, stress, and mass density distribution within the material, at its surface, and its immediate vacuum surroundings

Impact of supermassive black hole growth on star formation

Supermassive black holes are found at the centre of massive galaxies. During the growth of these black holes they light up to become visible as active galactic nuclei (AGN) and release extraordinary amounts of energy across the electromagnetic spectrum. This energy is widely believed to regulate the rate of star formation in the black holes' host galaxies via so-called "AGN feedback". However, the details of how and when this occurs remains uncertain from both an observational and theoretical perspective. I review some of the observational results and discuss possible observational signatures of the impact of super-massive black hole growth on star formation.Comment: Invited Review for Nature Astronomy - accepted for publication. 11 pages 6 figure

Parting the bamboo curtain: The enigmatic political and strategic quest of Richard Nixon for detente with Communist China

President Richard Nixon\u27s decision to unofficially recognize Communist China during the early 1970s represented an apparently sudden political and strategic turnabout for both he and the United States. After decades of virulent anti-Communism upon which a meteoric political career was built, Nixon, faced with mounting domestic pressures to end the Vietnam War and the necessity of obtaining policy concessions from the Soviet Union, embarked upon a course of detente with Mainland China that seemed to completely contradict his hawkish, Cold Warrior image. Far from being a strictly political maneuver in the months leading to the 1972 presidential election, Nixon\u27s decision was instead a pragmatic, geopolitical strategy designed as much to pressure the U.S.S.R. and balance the power in Asia as it was to bring the Chinese back into the world community of nations. Richard Nixon\u27s conservative background made the decision and subsequent Peking summit possible, as did his diplomatic partnership with Henry Kissinger

The potential of public participation geographic information systems in UK environmental planning: Appraisals by active publics

The paper draws on an empirical study of two workshops in which the issues that arise from the use of geographic information systems (GIS) as a planning tool in public participation settings were explored by local residents who take an active interest in local planning matters in their London borough. The paper demonstrates how issues concerned with the democratization of GIS and public participation GIS (PPGIS) informed the structure and conduct of the workshops and the qualitative analysis of the workshop discussions. Key themes raised by participants included: the potential of PPGIS as a means of extending knowledge networks; issues of data ownership and the responsiveness of data providers to public concerns; and the role that institutional norms and practices play in democratizing information availability and the transparency of the decision-making process. The paper concludes that the potential of PPGIS as a planning tool cannot be separated from public concerns about the legitimacy of the planning process or local government

Evaluation of the cardiovascular system during various circulatory stresses Progress report, 1 Jun. 1969 - 30 May 1970

Cardiovascular system evaluation during various circulatory stresse

Implications of cavity, topographic and geologic influences on tilt and strain observations

Tilt and strain observations are importantly (pathologically at the 100%, typically at the few 10s% level) affected by cavities, topography, and geological inhomogenities; gravity observation are practically unaffected. The traditional earth tide observatory and abandoned mine or tunnel is a very poor place to measure body tides because of the complicated cavities, topography and geology. Instead, the ideal site for observing the body tide is in flat terrain with horizontally layered, mechanically homogeneous geology. Strain will be measured with long surface- or trench-mounted laser strain meters and tilt with long, surface- or trench mounted liquid levels, or with borehole tiltmeters. Horizontal geological discontinuities can produce large perturbations of the tilt and strain tides, and these perturbations, using the known homogeneous tidal strains and tilts, can be used in exploring local structure in favorable cases and, through possible time variations of tidal admittances, in predicting earthquakes

Evaluation of the cardiovascular system during various circulatory stresses

Hardware and techniques for studying human circulatory performance in space environmen