2,822 research outputs found
The cutoff-dependence of the Casimir force within an inhomogeneous medium
We consider the ground state energy of the electromagnetic field in a piston
geometry. In the idealised case, where the piston and the walls of the chamber
are taken as perfect mirrors, the Casimir pressure on the piston is finite and
independent of the small scale physics of the media that compose the mirrors;
the Casimir-energy of the system can be regularised and is cutoff-independent.
Yet we find that, when the body of the piston is filled with an inhomogeneous
dielectric medium, the Casimir energy is cutoff-dependent, and the value of the
pressure is thus inextricably dependent on the detailed behaviour of the mirror
and the medium at large wave-vectors. This result is inconsistent with recent
proposals for regularising Casimir forces in inhomogeneous media.Comment: 6 pages, 2 figure
The pi-N Sigma term - a lattice investigation
A lattice calculation of the pi-N sigma term is described using dynamical
staggered fermions. Preliminary results give a sea term comparable in magnitude
to the valence term.Comment: Latex article. 6 pages, uuencoded compressed tar file. Contribution
to the Kyffhaeuser Workshop (Leipzig, Germany, September 1993). HLRZ preprint
93-6
The ``Spin'' Structure of the Nucleon - a lattice investigation
We will discuss here an indirect lattice evaluation of the baryon axial
singlet current matrix element. This quantity may be related to the fraction of
nucleon spin carried by the quarks. The appropriate structure function has
recently been measured (EMC experiment). As in this experiment, we find that
the quarks do not appear to carry a large component of the nucleon spin.Comment: Latex article. 3 pages. Contribution to the Second IMACS Conference
on Computational Physics, Cahokia, U.S.A. October 1993. HLRZ preprint 93-7
One-loop renormalisation for the second moment of GPDs with Wilson fermions
We calculate the non-forward quark matrix elements for operators with two
covariant derivatives in one-loop lattice perturbation theory using Wilson
fermions. These matrix elements are needed in the renormalisation of the second
moment of generalised parton distributions measured in lattice QCD. For some
commonly used representations of the hypercubic group we determine the sets of
all mixing operators and find the matrices of mixing and renormalisation
factors.Comment: Lattice 2004(improved), 3 pages, LaTeX style file, espcrc2.sty
include
Effective Yukawa Couplings in Noncompact Lattice QED
We investigate effective Yukawa couplings of mesons to the elementary
fermions in noncompact lattice QED. The couplings are extracted from suitable
fermion-antifermion-meson three-point functions calculated by Monte Carlo
simulations with dynamical staggered fermions. The scaling behaviour is
compatible with expectations from perturbation theory, thus indicating
triviality of QED. The lines of constant Yukawa coupling are compared to flows
of other quantities. Consistency is seen, at most, for weak coupling.Comment: 12 pages, uuencoded compressed postscrip
Hip Hop Feminism Starter Kit
The inspiration to develop a Hip Hop Feminist workbook developed from a college course I teach: Hip Hop Feminism: Queen B*tch. An Introduction to the (im)Possibilities of Hip Hop Feminism. Using the syllabus, I have developed lessons and talks on college campuses that I have also delivered to community spaces with Black girls and women, secondary educators, parents, and student organizations. I teach resistance and anti-establishment readings of our bodies, lyrics, and live and mediated performances of Hoes With An Attitude (H.W.A.) Lilâ Kim, Missy âMisdemeanorâ Elliott, Cardi B, The City Girls; as well as topics related to Hip Hop culture and sexual hygiene and wellness. I hope that youâre inspired to see the fullness of your magic, humanity, and beauty while gaining a sense of consciousness and intersectional thinking that happens when listening, dancing, lip syncing, or simply feeling a song. I encourage each of you to explore the healing and transformative power and pleasure experienced throughout Hip Hop culture
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