94,140 research outputs found
Time domain calculation of the electromagnetic self-force on eccentric geodesics in Schwarzschild spacetime
I calculate the self-force acting on a particle with electric charge q moving
on a generic geodesic around a Schwarzschild black hole. Using methods similar
to those developed for the scalar field case discussed in a previous paper, I
investigate the relative sizes of the conservative (half-advanced plus
half-retarded) and dissipative (half-advanced minus half-retarded) pieces of
the self-force. I also display the regularization parameters used in the
mode-sum regularization scheme.Comment: 24 pages; 21 figures; revtex
Can hierarchical predictive coding explain binocular rivalry?
Hohwy et al.’s (2008) model of binocular rivalry (BR) is taken as a classic illustration of predictive coding’s explanatory power. I revisit the account and show that it cannot explain the role of reward in BR. I then consider a more recent version of Bayesian model averaging, which recasts the role of reward in (BR) in terms of optimism bias. If we accept this account, however, then we must reconsider our conception of perception. On this latter view, I argue, organisms engage in what amounts to policy-driven, motivated perception
Sovereign debt: Do we need an EU solution? Bertelsmann Stiftung EUROPA Briefing 2017
High levels of sovereign debt have become a serious issue in the Eurozone. This
does not just affect the individual member states: The European debt crisis has
shown that difficulties in one euro-area country can spread to the entire currency
union. What strategies are being discussed for reducing sovereign debt? Would a
stronger role for the EU help to reduce debt over the long term or should this be
left solely to the member states
Airborne electromagnetic sea ice thickness sounding in shallow, brackish water environments of the Caspian and Baltic Seas
Ice engineering projects often rely on the knowledge of ice thickness in shallow, brackish water like in the Baltic and Caspian Seas. By means of field data and model results, the paper shows that helicopter-borne electromagnetic induction measurements using frequencies of 3.68 and 112 kHz can yield accurate thickness estimates with salinities as low as 3 ppt. The higher frequency yields the strongest EM signals. In addition, in shallow water the higher frequency is less sensitive to the sea floor signal, and can thus be used in water depths as shallow as 4-6 m, depending on flying altitude. Because the low frequency signal is very sensitive on shallow water depth, a combination of both signals will allow the retrieval of both ice thickness and water depth
- …