Crustal deformation at very long baseline interferometry sites due to seasonal air-mass and ground water variations

The seasonal deformation normal to the Earth's surface was calculated at stations involved or interested in very long baseline interferometry (VLBI) geodesy and at hypothetical sites in Australia and Brazil using global atmospheric pressure data, values for groundwater storage, and load Love numbers deduced from current Earth models. It was found that the annual range of deformation approached the centimeter level measuring potential of the VLBI technqiue at Greenbank, Haystack, and the Brazil site

Correlations Estimates in the Lattice Anderson Model

We give a new proof of correlation estimates for arbitrary moments of the resolvent of random Schr\"odinger operators on the lattice that generalizes and extends the correlation estimate of Minami for the second moment. We apply this moment bound to obtain a new $n$-level Wegner-type estimate that measures eigenvalue correlations through an upper bound on the probability that a local Hamiltonian has at least $n$ eigenvalues in a given energy interval. Another consequence of the correlation estimates is that the results on the Poisson statistics of energy level spacing and the simplicity of the eigenvalues in the strong localization regime hold for a wide class of translation-invariant, selfadjoint, lattice operators with decaying off-diagonal terms and random potentials.Comment: 16 page

Isaac of Stella, the Cistercians and the Thomas Becket Controversy: A Bibliographical and Contextual Study

Isaac of Stella (ca. 1100-ca. 1169), an English-born Cistercian and abbot, has been dwarfed by Bernard of Clairvaux and other of his twelfth-century Cistercian contemporaries in terms of literary output and influence, giving him a reputation as an elusive and marginal figure. Isaac\u27s 55 sermons and two treatises are modest compared to the productivity of other monastic writers and his position as the abbot of an obscure monastery in western France has not helped to raise his visibility among the luminaries of the twelfth century. He is remembered as a mysterious and often tragic figure in the annals of history. Recent scholarship has shed light on this elusive abbot. One area of his life that has attracted some attention has been Isaac\u27s involvement in the controversy between Henry II (1133-89) and Thomas Becket (ca. 1120-70), archbishop of Canterbury. Gaetano Raciti in particular has argued that Isaac\u27s involvement in the Becket controversy, specifically siding with Becket in the archbishop\u27s quarrel with the king, led to Isaac\u27s exile to the island of Ré and the loss of his abbacy. Raciti\u27s research, which continues to be influential, focused on Isaac\u27s sermons and from them he compiled numerous biographical and historical clues to piece together Isaac\u27s ultimate downfall as abbot. But Raciti\u27s interpretations have been reconsidered by a few scholars, initially by Claude Garda as well as the subsequent research of Ferruccio Gastaldelli and Elias Dietz. In this dissertation, I continue the reconsideration of Raciti\u27s interpretations. In particular I focus on Isaac\u27s role as a monk as well as his continuity with the Christian monastic tradition. Contrary to Raciti\u27s interpretations, I demonstrate that Isaac\u27s support of Becket was minimal and not the cause of serious consequences affecting his abbacy. This demonstration is based on reading Isaac\u27s sermons not as sources of either biographical or historical data but rather as monastic sermons. Isaac\u27s sermons provide proof of his continuity with his monastic forbears and place them in their proper theological and monastic context. Isaac emerges as neither mysterious nor tragic but rather as a monk who wrote for monks

Interacting multi-component exciton gases in a potential trap: phase separation and Bose-Einstein condensation

The system under consideration is a multi-component gas of interacting para- and orthoexcitons confined in a three dimensional potential trap. We calculate the spatially resolved optical emission spectrum due to interband transitions involving weak direct and phonon mediated exciton-photon interactions. For each component, the occurrence of a Bose-Einstein condensate changes the spectrum in a characteristic way so that it directly reflects the constant chemical potential of the excitons and the renormalization of the quasiparticle excitation spectrum. Moreover, the interaction between the components leads, in dependence on temperature and particle number, to modifications of the spectra indicating phase separation of the subsystems. Typical examples of density profiles and luminescence spectra of ground-state para- and orthoexcitons in cuprous oxide are given.Comment: 7 pages, 6 figure

Results of the Australian geodetic VLBI experiment

The 250-2500 km baseline vectors between radio telescopes located at Tidbinbilla (DSS43) near Canberra, Parkes, Fleurs (X3) near Sydney, Hobart and Alice Springs were determined from radio interferometric observations of extragalactic sources. The observations were made during two 24-hour sessions on 26 April and 3 May 1982, and one 12-hour night-time session on 28 April 1982. The 275 km Tidbinbilla - Parkes baseline was measured with an accuracy of plus or minus 6 cm. The remaining baselines were measured with accuracies ranging from 15 cm to 6 m. The higher accuracies were achieved for the better instrumented sites of Tidbinbilla, Parkes and Fleurs. The data reduction technique and results of the experiment are discussed

Positivity of Lyapunov exponents for a continuous matrix-valued Anderson model

We study a continuous matrix-valued Anderson-type model. Both leading Lyapunov exponents of this model are proved to be positive and distinct for all ernergies in $(2,+\infty)$ except those in a discrete set, which leads to absence of absolutely continuous spectrum in $(2,+\infty)$. This result is an improvement of a previous result with Stolz. The methods, based upon a result by Breuillard and Gelander on dense subgroups in semisimple Lie groups, and a criterion by Goldsheid and Margulis, allow for singular Bernoulli distributions

Half-life Limit of 19Mg

A search for 19Mg was performed using projectile fragmentation of a 150 MeV/nucleon 36Ar beam. No events of 19Mg were observed. From the time-of-flight through the fragment separator an upper limit of 22 ns for the half-life of 19Mg was established