4,989 research outputs found
Informational Inequality: How High Frequency Traders Use Premier Access to Information to Prey on Institutional Investors
In recent months, Wall Street has been whipped into a frenzy following the March 31st release of Michael Lewis’ book “Flash Boys.” In the book, Lewis characterizes the stock market as being rigged, which has institutional investors and outside observers alike demanding some sort of SEC action. The vast majority of this criticism is aimed at high-frequency traders, who use complex computer algorithms to execute trades several times faster than the blink of an eye. One of the many complaints against high-frequency traders is over parasitic trading practices, such as front-running. Front-running, in the era of high-frequency trading, is best defined as using the knowledge of a large impending trade to take a favorable position in the market before that trade is executed. Put simply, these traders are able to jump in front of a trade before it can be completed. This Note explains how high-frequency traders are able to front-run trades using superior access to information, and examines several proposed SEC responses
Solar neutrinos, helioseismology and the solar internal dynamics
Neutrinos are fundamental particles ubiquitous in the Universe. Their
properties remain elusive despite more than 50 years of intense research
activity. In this review we remind the reader of the noticeable properties of
these particles and of the stakes of the solar neutrino puzzle. The Standard
Solar Model triggered persistent efforts in fundamental Physics to predict the
solar neutrino fluxes, and its constantly evolving predictions have been
regularly compared to the detected neutrino signals. Anticipating that this
standard model could not reproduce the internal solar dynamics, a SEismic Solar
Model was developed which enriched theoretical neutrino flux predictions with
in situ observation of acoustic waves propagating in the Sun. This review
reminds the historical steps, from the pioneering Homestake detection, the
GALLEX- SAGE captures of the first pp neutrinos and emphasizes the importance
of the Superkamiokande and SNO detectors to demonstrate that the solar-emitted
electronic neutrinos are partially transformed into other neutrino flavors
before reaching the Earth. The success of BOREXINO in detecting the 7 Be
neutrino signal justifies the building of a new generation of detectors to
measure the entire solar neutrino spectrum. A coherent picture emerged from
neutrino physics and helioseismology. Today, new paradigms take shape:
determining the masses of neutrinos and the research on the Sun is focusing on
the dynamical aspects and on signature of dark matter. The third part of the
review is dedicated to this prospect. The understanding of the crucial role of
both rotation and magnetism in solar physics benefit from SoHO, SDO, and PICARD
space observations. For now, the particle and stellar challenges seem
decoupled, but this is only a superficial appearance. The development of
asteroseismology shows the far-reaching impact of Neutrino and Stellar
Astronomy.Comment: 60 pages, 12 figures Invited review in press in Report on Progress in
Physic
Dark Matter investigation by DAMA at Gran Sasso
Experimental observations and theoretical arguments at Galaxy and larger
scales have suggested that a large fraction of the Universe is composed by Dark
Matter particles. This has motivated the DAMA experimental efforts to
investigate the presence of such particles in the galactic halo by exploiting a
model independent signature and very highly radiopure set-ups deep underground.
Few introductory arguments are summarized before presenting a review of the
present model independent positive results obtained by the DAMA/NaI and
DAMA/LIBRA set-ups at the Gran Sasso National Laboratory of the INFN.
Implications and model dependent comparisons with other different kinds of
results will be shortly addressed. Some arguments put forward in literature
will be confuted.Comment: review article, 71 pages, 25 figures, 8 tables; v2: minor
modifications. In publication on the International Journal of Modern Physics
A Proposal for a Three Detector Short-Baseline Neutrino Oscillation Program in the Fermilab Booster Neutrino Beam
A Short-Baseline Neutrino (SBN) physics program of three LAr-TPC detectors
located along the Booster Neutrino Beam (BNB) at Fermilab is presented. This
new SBN Program will deliver a rich and compelling physics opportunity,
including the ability to resolve a class of experimental anomalies in neutrino
physics and to perform the most sensitive search to date for sterile neutrinos
at the eV mass-scale through both appearance and disappearance oscillation
channels. Using data sets of 6.6e20 protons on target (P.O.T.) in the LAr1-ND
and ICARUS T600 detectors plus 13.2e20 P.O.T. in the MicroBooNE detector, we
estimate that a search for muon neutrino to electron neutrino appearance can be
performed with ~5 sigma sensitivity for the LSND allowed (99% C.L.) parameter
region. In this proposal for the SBN Program, we describe the physics analysis,
the conceptual design of the LAr1-ND detector, the design and refurbishment of
the T600 detector, the necessary infrastructure required to execute the
program, and a possible reconfiguration of the BNB target and horn system to
improve its performance for oscillation searches.Comment: 209 pages, 129 figure
TESLA Technical Design Report Part III: Physics at an e+e- Linear Collider
The TESLA Technical Design Report Part III: Physics at an e+e- Linear
ColliderComment: 192 pages, 131 figures. Some figures have reduced quality. Full
quality figures can be obtained from http://tesla.desy.de/tdr. Editors -
R.-D. Heuer, D.J. Miller, F. Richard, P.M. Zerwa
A formal approach for network security policy validation
Network security is a crucial aspect for administrators due to increasing network size and number of functions and controls (e.g.firewall, DPI, parental control).
Errors in configuring security controls may result in serious security breaches and vulnerabilities (e.g. blocking legitimate traffic or permitting unwanted traffic) that must be absolutely detected and addressed.
This work proposes a novel approach for validating network policy enforcement, by checking the network status and configuration, and detection of the possible causes in case of misconfiguration or software attacks.
Our contribution exploits formal methods to model and validate the packet processing and forwarding behaviour of security controls, and to validate the trustworthiness of the controls by using remote attestation.
A prototype implementation of this approach is proposed to validate different scenarios
Proceedings of the Workshop on Monte Carlo's, Physics and Simulations at the LHC PART II
These proceedings collect the presentations given at the first three meetings
of the INFN "Workshop on Monte Carlo's, Physics and Simulations at the LHC",
held at the Frascati National Laboratories in 2006. The first part of these
proceedings contains pedagogical introductions to several basic topics of both
theoretical and experimental high pT LHC physics. The second part collects more
specialised presentations.Comment: 157 pages, 136 figures; contribution by M. Grazzini has been adde
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