3,901 research outputs found
Analysis of binary trading patterns in Xetra
This paper proposes the Shannon entropy as an appropriate one-dimensional measure of behavioural trading patterns in financial markets. The concept is applied to the illustrative example of algorithmic vs. non-algorithmic trading and empirical data from Deutsche Börse's electronic cash equity trading system, Xetra. The results reveal pronounced differences between algorithmic and non-algorithmic traders. In particular, trading patterns of algorithmic traders exhibit a medium degree of regularity while non-algorithmic trading tends towards either very regular or very irregular trading patterns. JEL Classification: C40, D0, G14, G15, G2
Energy loss in a partonic transport model including bremsstrahlung processes
A detailed investigation of the energy loss of gluons that traverse a thermal
gluonic medium simulated within the perturbative QCD--based transport model
BAMPS (a Boltzmann approach to multiparton scatterings) is presented in the
first part of this work. For simplicity the medium response is neglected in
these calculations. The energy loss from purely elastic interactions is
compared to the case where radiative processes are consistently included based
on the matrix element by Gunion and Bertsch. From this comparison gluon
multiplication processes gg -> ggg are found to be the dominant source of
energy loss within the approach employed here. The consequences for the
quenching of gluons with high transverse momentum in fully dynamic simulations
of Au+Au collisions at the RHIC energy of sqrt(s) = 200 AGeV are discussed in
the second major part of this work. The results for central collisions as
discussed in a previous publication are revisited and first results on the
nuclear modification factor R_AA for non-central Au+Au collisions are
presented. They show a decreased quenching compared to central collisions while
retaining the same shape. The investigation of the elliptic flow v2 is extended
up to non-thermal transverse momenta of 10 GeV, exhibiting a maximum v2 at
roughly 4 to 5 GeV and a subsequent decrease. Finally the sensitivity of the
aforementioned results on the specific implementation of the effective modeling
of the Landau-Pomeranchuk-Migdal (LPM) effect via a formation time based
cut-off is explored.Comment: 40 pages, 20 figures, 1 tabl
Renormalization group flows into phases with broken symmetry
We describe a way to continue the fermionic renormalization group flow into
phases with broken global symmetry. The method does not require a
Hubbard-Stratonovich decoupling of the interaction. Instead an infinitesimally
small symmetry-breaking component is inserted in the initial action, as an
initial condition for the flow of the selfenergy. Its flow is driven by the
interaction and at low scales it saturates at a nonzero value if there is a
tendency for spontaneous symmetry breaking in the corresponding channel. For
the reduced BCS model we show how a small initial gap amplitude flows to the
value given by the exact solution of the model. We also discuss the emergence
of the Goldstone boson in this approach.Comment: 30 pages, LaTeX, 8 figure
Work and the Lodge: Fraternalism in Meridan and New Britain, Connecticut
http://deepblue.lib.umich.edu/bitstream/2027.42/50932/1/157.pd
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