3,136 research outputs found
Real time statistical field theory
We have written a {\it Mathematica} program that calculates the integrand
corresponding to any amplitude in the closed-time-path formulation of real time
statistical field theory. The program is designed so that it can be used by
someone with no previous experience with {\it Mathematica}. It performs the
contractions over the tensor indices that appear in real time statistical field
theory and gives the result in the 1-2, Keldysh or RA basis. We have used the
program to calculate the ward identity for the QED 3-point function, the QED
4-point function for two photons and two fermions, and the QED 5-point function
for three photons and two fermions. In real time statistical field theory,
there are seven 3-point functions, 15 4-point functions and 31 5-point
functions. We produce a table that gives the results for all of these
functions. In addition, we give a simple general expression for the KMS
conditions between -point green functions and vertex functions, in both the
Keldysh and RA basesComment: 25 pages, 12 figure
Letter from W. T. Carrington
Letter concerning a department of Domestic Science at Missouri State University
Spontaneous Symmetry Breaking for Scalar QED with Non-minimal Chern-Simons Coupling
We investigate the two-loop effective potential for both minimally and
non-minimally coupled Maxwell-Chern-Simons theories. The non-minimal gauge
interaction represents the magnetic moment interaction between a charged scalar
and the electromagnetic field. In a previous paper we have shown that the two
loop effective potential for this model is renormalizable with an appropriate
choice of the non-minimal coupling constant. We carry out a detailed analysis
of the spontaneous symmetry breaking induced by radiative corrections. As long
as the renormalization point for all couplings is chosen to be the true minimum
of the effective potential, both models predict the presence of spontaneous
symmetry breaking. Two loop corrections are small compared to the one loop
result, and thus the symmetry breaking is perturbatively stable.Comment: Revtex 25 pages, 9 figure
Letter from W. [T. ?] Carrington to John Muir, [ca. 1898].
To my honored friend & fellow passenger on board the Kaiserin Auguste VictoriaMr. John MuirFrom a home where the latchstring is always out for you, where the hearthstone is ever warm for you, and where the music of your step and voice finds ever a waiting welcome.W.T. CarringtonGreenwich Conn.Tel. 284Port Chester N.Y.New York540 Park Ave.Tel. 53190987
Abstract appeals to free speech won’t solve the debate surrounding Confederate monuments—it’s a political question
This month has seen the most recent push to remove Confederate statues in cities across the Southern US. Nathan T. Carrington and Logan Strother unpack the argument made by some who support the statues that their removal flies in the face of freedom of speech. They argue that questions over the fate of Confederate monuments are by their nature, political
Infrared behaviour of the pressure in g\phi^3 theory in 6 dimensions
In an earlier paper Almeida and Frenkel considered the calculation of the
pressure in g\phi^3 theory in 6 dimensions via the Schwinger--Dyson equation.
They found, under certain approximations, that a finite result ensues in the
infrared limit. We find this conclusion to remain true with certain variations
of these approximations, suggesting the finiteness of the result to be fairly
robust.Comment: 6 pages, 4 figures, uses revtex
Multi-sensor Testing for Automated Rendezvous and Docking
During the past two years, many sensors have been tested in an open-loop fashion in the Marshall Space Flight Center (MSFC) Flight Robotics Laboratory (FRL) to both determine their suitability for use in Automated Rendezvous and Docking (AR&D) systems and to ensure the test facility is prepared for future multi-sensor testing. The primary focus of this work was in support of the CEV AR&D system, because the AR&D sensor technology area was identified as one of the top risks in the program. In 2006, four different sensors were tested individually or in a pair in the MSFC FRL. In 2007, four sensors, two each of two different types, were tested simultaneously. In each set of tests, the target was moved through a series of pre-planned trajectories while the sensor tracked it. In addition, a laser tracker "truth" sensor also measured the target motion. The tests demonstrated the functionality of testing four sensors simultaneously as well as the capabilities (both good and bad) of all of the different sensors tested. This paper outlines the test setup and conditions, briefly describes the facility, summarizes the earlier results of the individual sensor tests, and describes in some detail the results of the four-sensor testing. Post-test analysis includes data fusion by minimum variance estimation and sequential Kalman filtering. This Sensor Technology Project work was funded by NASA's Exploration Technology Development Program
Energy Flow in Acoustic Black Holes
We present the results of an analysis of superradiant energy flow due to
scalar fields incident on an acoustic black hole. In addition to providing
independent confirmation of the recent results in [5], we determine in detail
the profile of energy flow everywhere outside the horizon. We confirm
explicitly that in a suitable frame the energy flow is inward at the horizon
and outward at infinity, as expected on physical grounds.Comment: 8 pages, 9 figures, Comments added to discussion of energy flow and
introductory section abbreviate
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