Application of graphics processing units to search pipelines for gravitational waves from coalescing binaries of compact objects

We report a novel application of a graphics processing unit (GPU) for the purpose of accelerating the search pipelines for gravitational waves from coalescing binaries of compact objects. A speed-up of 16-fold in total has been achieved with an NVIDIA GeForce 8800 Ultra GPU card compared with one core of a 2.5 GHz Intel Q9300 central processing unit (CPU). We show that substantial improvements are possible and discuss the reduction in CPU count required for the detection of inspiral sources afforded by the use of GPUs

Information-Based Trading and the Bid-Ask Spread

We analyze the equilibrium spread when the transaction size of informed traders is elastic in the value of private information (α). We show that the pooling equilibrium is likely to be inefficient when trade size is sensitive to α and the inefficient equilibrium can occur before the market breaks down. The pooling equilibrium spread does not monotonically increase with α, although it increases with the elasticity of informed trades to α. The upper bound of the elasticity of informed trades for the market to remain open for the active specialist is higher than the corresponding value for the passive specialist when the specialist has enough leverage over brokers

Signatures of Electronic Nematic Phase at Isotropic-Nematic Phase Transition

The electronic nematic phase occurs when the point-group symmetry of the lattice structure is broken, due to electron-electron interactions. We study a model for the nematic phase on a square lattice with emphasis on the phase transition between isotropic and nematic phases within mean field theory. We find the transition to be first order, with dramatic changes in the Fermi surface topology accompanying the transition. Furthermore, we study the conductivity tensor and Hall constant as probes of the nematic phase and its transition. The relevance of our findings to Hall resistivity experiments in the high-$T_c$ cuprates is discussed.Comment: 5 pages, 3 figure

The Dynamics of Quote Adjustments

Liquidity providers on the NYSE make faster quote adjustments towards equilibrium spreads and depths than they do on NASDAQ. Liquidity providers in both markets make faster spread and depth adjustments for stocks with more frequent trading, greater return volatility, higher prices, smaller market capitalizations, and smaller trade sizes. We find that stocks with greater information-based trading and in more competitive trading environments exhibit faster quote adjustments. The speed of quote adjustment is faster after decimalization in both markets. These results are robust and not driven by differences in stock attributes between the two markets or time periods. Overall, our results indicate that stock attributes, market structure, and tick size exert a significant impact on the speed of quote adjustment

Accelerated Searches of Gravitational Waves Using Graphics Processing Units

The existence of gravitational waves was predicted by Albert Einstein. Black hole and neutron star binary systems will product strong gravitational waves through their inspiral and eventual merger. The analysis of the gravitational wave data is computationally intensive, requiring matched filtering of terabytes of data with a bank of at least 3000 numerical templates that represent predicted waveforms. We need to complete the analysis in real‐time (within the duration of the signal) in order to enable follow‐up observations with some conventional optical or radio telescopes. We report a novel application of a graphics processing units (GPUs) for the purpose of accelerating the search pipelines for gravitational waves from coalescing binary systems of compact objects. A speed‐up of 16 fold in total has been achieved with an NVIDIA GeForce 8800 Ultra GPU card compared with a standard central processing unit (CPU). We show that further improvements are possible and discuss the reduction in CPU number required for the detection of inspiral sources afforded by the use of GPUs