17,825 research outputs found
EPR Test with Photons and Kaons: Analogies
We present a unified formalism describing EPR test using spin 1/2 particles,
photons and kaons. This facilitates the comparison between existing experiments
using photons and kaons. It underlines the similarities between birefringence
and polarization dependent losses that affects experiments using optical fibers
and mixing and decay that are intrinsic to the kaons. We also discuss the
limitation these two characteristics impose on the testing of Bell's
inequality.Comment: 12 pages, 5 figure
Observation of Bell Inequality violation in B mesons
A pair of mesons from decay exhibit EPR type
non-local particle-antiparticle (flavor) correlation. It is possible to write
down Bell Inequality (in the CHSH form: ) to test the non-locality
assumption of EPR. Using semileptonic decays of at Belle
experiment, a clear violation of Bell Inequality in particle-antiparticle
correlation is observed:
S=2.725+-0.167(stat)+-0.092(syst)Comment: Conference Proceeding for Garda Lake Workshop 2003 "Mysteries,
Puzzles and Paradoxes in Quantum Mechanics
CP Measurement in Quantum Teleportation of Neutral Mesons
Quantum teleportation using neutral pseudoscalar mesons shows novel
connections between particle physics and quantum information. The projection
basis, which is crucial in the teleportation process, is determined by the
conservation laws of particle physics, and is different from the Bell basis, as
in the usual case. Here we show that one can verify the teleportation process
by CP measurement. This method significantly simplifies the high energy quantum
teleportation protocol. Especially, it is rigorous, and is independent of
whether CP is violated in weak decays. This method can also be applied to
general verification of Einstein-Podolsky-Rosen correlations in particle
physics.Comment: 7 page
On predictability of rare events leveraging social media: a machine learning perspective
Information extracted from social media streams has been leveraged to
forecast the outcome of a large number of real-world events, from political
elections to stock market fluctuations. An increasing amount of studies
demonstrates how the analysis of social media conversations provides cheap
access to the wisdom of the crowd. However, extents and contexts in which such
forecasting power can be effectively leveraged are still unverified at least in
a systematic way. It is also unclear how social-media-based predictions compare
to those based on alternative information sources. To address these issues,
here we develop a machine learning framework that leverages social media
streams to automatically identify and predict the outcomes of soccer matches.
We focus in particular on matches in which at least one of the possible
outcomes is deemed as highly unlikely by professional bookmakers. We argue that
sport events offer a systematic approach for testing the predictive power of
social media, and allow to compare such power against the rigorous baselines
set by external sources. Despite such strict baselines, our framework yields
above 8% marginal profit when used to inform simple betting strategies. The
system is based on real-time sentiment analysis and exploits data collected
immediately before the games, allowing for informed bets. We discuss the
rationale behind our approach, describe the learning framework, its prediction
performance and the return it provides as compared to a set of betting
strategies. To test our framework we use both historical Twitter data from the
2014 FIFA World Cup games, and real-time Twitter data collected by monitoring
the conversations about all soccer matches of four major European tournaments
(FA Premier League, Serie A, La Liga, and Bundesliga), and the 2014 UEFA
Champions League, during the period between Oct. 25th 2014 and Nov. 26th 2014.Comment: 10 pages, 10 tables, 8 figure
Properties of the one-dimensional Hubbard model: cellular dynamical mean-field description
The one-dimensional half-filled Hubbard model is considered at zero
temperature within the cellular dynamical mean-field theory (CDMFT). By the
computation of the spectral gap and the energy density with various cluster and
bath sizes we examine the accuracy of the CDMFT in a systematic way, which
proves the accurate description of the one-dimensional systems by the CDMFT
with small clusters. We also calculate the spectral weights in a full range of
the momentum for various interaction strengths. The results do not only account
for the spin-charge separation, but they also reproduce all the features of the
Bethe ansatz dispersions, implying that the CDMFT provides an excellent
description of the spectral properties of low-dimensional interacting systems.Comment: J. Phys.: Condens. Matter, in pres
Multiplicative random walk Metropolis-Hastings on the real line
In this article we propose multiplication based random walk Metropolis
Hastings (MH) algorithm on the real line. We call it the random dive MH (RDMH)
algorithm. This algorithm, even if simple to apply, was not studied earlier in
Markov chain Monte Carlo literature. The associated kernel is shown to have
standard properties like irreducibility, aperiodicity and Harris recurrence
under some mild assumptions. These ensure basic convergence (ergodicity) of the
kernel. Further the kernel is shown to be geometric ergodic for a large class
of target densities on . This class even contains realistic target
densities for which random walk or Langevin MH are not geometrically ergodic.
Three simulation studies are given to demonstrate the mixing property and
superiority of RDMH to standard MH algorithms on real line. A share-price
return data is also analyzed and the results are compared with those available
in the literature
Bell's inequality tests: from photons to B-mesons
We analyse the recent claim that a violation of a Bell's inequality has been
observed in the --meson system [A. Go, {\em Journal of Modern Optics} {\bf
51} (2004) 991]. The results of this experiment are a convincing proof of
quantum entanglement in --meson pairs similar to that shown by polarization
entangled photon pairs. However, we conclude that the tested inequality is not
a genuine Bell's inequality and thus cannot discriminate between quantum
mechanics and local realistic approaches.Comment: 5 page
How Course 2-A is paving the way for interdisciplinary engineering education at MIT
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 38).In 2004, The National Academy of Engineers (NAE) released a report calling for changes to be made to the current engineering education system in response to the growing need for engineering graduates who would be able to understand engineering problems in a larger context. The present study hopes to gain a better understanding of the growth of flexible engineering education by determining differences in student characteristics and their effect on a student's choice of academic program, identifying the perceptions of the MIT community of flexible and traditional engineering programs and how these perceptions changed over time, and establishing whether or not a correlation exists between students' perceived self-efficacy in engineering and professional abilities and his or her career plans. An online survey was developed and administered to the Course 2 and Course 2-A student body. Significant differences in motivation, opinion of Course 2 and Course 2-A, as well as perceived self-efficacy were found between Course 2 and Course 2-A students.by Shanette A. Go.S.B
Generation of bipartite spin entanglement via spin-independent scattering
We consider the bipartite spin entanglement between two identical fermions
generated in spin-independent scattering. We show how the spatial degrees of
freedom act as ancillas for the creation of entanglement to a degree that
depends on the scattering angle, . The number of Slater determinants
generated in the process is greater than 1, corresponding to genuine quantum
correlations between the identical fermions. The maximal entanglement
attainable of 1 ebit is reached at . We also analyze a simple
dependent Bell's inequality, which is violated for
. This phenomenon is unrelated to the symmetrization
postulate but does not appear for unequal particles.Comment: 5 pages and 3 figures. Accepted in PR
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