25,411 research outputs found
Information Storage in Black Holes
The information loss paradox for Schwarzschild black holes is examined, using
the ADS/CFT correspondence extended to the bulk. It is found that
the only option compatible with the preservation of the quantum unitarity is
when a regular remnant region of the black hole survives to the black hole
evaporation process, where information can be stored and eventually retrieved.Comment: 5 pages Latex file, no figures. A honourable mention in the 2005 GRF
essay competitio
Simulation of charged particle trajectories in the neutron decay correlation experiment abBA
The proposed neutron decay correlation experiment, abBA, will directly detect the direction of emission of decay protons and electrons as well as providing spectroscopic information for both particles. In order to provide this information, the abBA experiment incorporates spatially varying electric and magnetic fields. We report on detailed simulations of the decay particle trajectories in order to assess the impact of various systematic effects on the experimental observables. These include among others; adiabaticity of particle orbits, tracking of orbits, reversal of low energy protons due to inhomogeneous electric field, and accuracy of proton time of flight measurements. Several simulation methods were used including commercial software (Simion), custom software, as well as analytical tools based on the use of adiabatic invariants. Our results indicate that the proposed field geometry of the abBA spectrometer will be substantially immune to most systematic effects and that transport calculations using adiabatic invariants agree well with solution of the full equations of motion
Exciton-magnon effects in the optical spectrum of MnF2
Exciton and magnon absorption, emission spectra, and fluorescence of antiferromagnetic manganese fluorid
A Comparison of Conventional and Organic Milk Production Systems in the U.S.
Replaced with revised version of paper 07/23/07.Farm Management,
The Profitability of Organic Soybean Production
Results from long-term experimental trials suggest that similar yields and lower costs are possible with organic compared to conventional soybeans, but there is little information about the relative costs and returns on commercial farms. This study examines the profitability of commercial soybean production using a nationwide survey of soybean producers for 2006 that includes a targeted sample of organic growers. Treatment-effect models are specified to isolate the impact of choosing the organic approach on various levels of soybean production costs. Organic soybean costs range from about 6 per bushel higher than those for conventional soybeans due to both lower yields and higher per-acre costs, while the average organic price premium in 2006 is more than $9 per bushel. High returns to organic production are attributed to the significant price premiums paid for organic soybeans in 2006, and these price premiums have remained high in 2007 and 2008. However, much higher conventional soybean prices and increased fuel prices may have reduced the incentive for planting organic soybeans.Crop Production/Industries,
Advanced propellant management system for spacecraft propulsion systems. Phase 1 - Survey study and evaluation
Apollo spacecraft propulsion system propellant managemen
Resonant decay of parity odd bubbles in hot hadronic matter
We investigate the decay of metastable states with broken CP-symmetry which
have recently been proposed by Kharzeev, Pisarski and Tytgat to form in hot
hadronic matter. We consider the efficiency of the amplification of the
-field via parametric resonance, taking the backreaction into account.
For times of the order , we find a particle density of about
and a correlation length of . The
corresponding momentum spectra show a non-thermal behaviour.Comment: 11 pages latex file with 4 gif - figures. Uses elsart.cls (included
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