University of Warsaw

About: University of Warsaw is a education organization based out in Warsaw, Poland. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 20832 authors who have published 56617 publications receiving 1185084 citations. The organization is also known as: Uniwersytet Warszawski & Warsaw University.

Characterization of transient noise in Advanced LIGO relevant to gravitational wave signal GW150914

Abstract: On 14 September 2015, a gravitational wave signal from a coalescing black hole binary system was observed by the Advanced LIGO detectors. This paper describes the transient noise backgrounds used to determine the significance of the event (designated GW150914) and presents the results of investigations into potential correlated or uncorrelated sources of transient noise in the detectors around the time of the event. The detectors were operating nominally at the time of GW150914. We have ruled out environmental influences and non-Gaussian instrument noise at either LIGO detector as the cause of the observed gravitational wave signal.

Measurement of the Bs0→μ+μ- branching fraction and search for B0→μ+μ- with the CMS experiment

Abstract: Results are presented from a search for the rare decays B0s→μ+μ− and B0→μ+μ− in pp collisions at s√=7 and 8 TeV, with data samples corresponding to integrated luminosities of 5 and 20 fb−1, respectively, collected by the CMS experiment at the LHC. An unbinned maximum-likelihood fit to the dimuon invariant mass distribution gives a branching fraction B(B0s→μ+μ−)=(3.0+1.0−0.9)×10−9, where the uncertainty includes both statistical and systematic contributions. An excess of B0s→μ+μ− events with respect to background is observed with a significance of 4.3 standard deviations. For the decay B0→μ+μ− an upper limit of B(B0→μ+μ−)<1.1×10−9 at the 95% confidence level is determined. Both results are in agreement with the expectations from the standard model.

Proofs of Space

Abstract: Proofs of work (PoW) have been suggested by Dwork and Naor (Crypto’92) as protection to a shared resource. The basic idea is to ask the service requestor to dedicate some non-trivial amount of computational work to every request. The original applications included prevention of spam and protection against denial of service attacks. More recently, PoWs have been used to prevent double spending in the Bitcoin digital currency system.

Classical Theory of Electronic and Ionic Inelastic Collisions

Abstract: A classical theory of inelastic atomic collisions is given. It is shown that inelastic scattering, ionization, excitation, and other interactions between charged particles and atoms are due to the Coulomb interaction with atomic electrons and depend in a first approximation on their binding energy and momentum distribution. All cross sections can easily be calculated by means of differential cross sections $\ensuremath{\sigma}(\ensuremath{\Delta}E)$ and $\ensuremath{\sigma}(\ensuremath{\Delta}E, \ensuremath{\vartheta})$ derived in the binary encounter approximation. Numerical calculations have been made for several cases and are in very good agreement with the experimental results.

Continuum molecular electrostatics, salt effects, and counterion binding—A review of the Poisson–Boltzmann theory and its modifications

Abstract: This work is a review of the Poisson-Boltzmann (PB) continuum electrostatics theory and its modifications, with a focus on salt effects and counterion binding. The PB model is one of the mesoscopic theories that describes the electrostatic potential and equilibrium distribution of mobile ions around molecules in solution. It serves as a tool to characterize electrostatic properties of molecules, counterion association, electrostatic contributions to solvation, and molecular binding free energies. We focus on general formulations which can be applied to large molecules of arbitrary shape in all-atomic representation, including highly charged biomolecules such as nucleic acids. These molecules present a challenge for theoretical description, because the conventional PB model may become insufficient in those cases. We discuss the conventional PB equation, the corresponding functionals of the electrostatic free energy, including a connection to DFT, simple empirical extensions to this model accounting for finite size of ions, the modified PB theory including ionic correlations and fluctuations, the cell model, and supplementary methods allowing to incorporate site-bound ions in the PB calculations.