99,514 research outputs found
Competition, Trade, and the Antitrust Division: 1981
One of the primary purposes-some would say the primary pur- pose--of antitrust laws is to promote efficient allocation of resources and maximum consumer choice by preventing and punishing artificial barriers to competition and unreasonable restraints of trade.\u27 The An- titrust Division of the U.S. Department of Justice has therefore con- cerned itself with the task of breaking down those barriers. In the domestic field, this policy has traditionally taken the form of prosecut- ing persons and corporations who engage in price fixing or market divi- sion, or who obtain or maintain monopoly power by means of abusive practices. More recently, the Antitrust Division, while continuing its attack on private restraints, has opened a second front by seeking to narrow the scope of, or to abolish government regulations which em- body or facilitate restrictions on competition
Competition, Trade, and the Antitrust Division: 1981
One of the primary purposes-some would say the primary pur- pose--of antitrust laws is to promote efficient allocation of resources and maximum consumer choice by preventing and punishing artificial barriers to competition and unreasonable restraints of trade.\u27 The An- titrust Division of the U.S. Department of Justice has therefore con- cerned itself with the task of breaking down those barriers. In the domestic field, this policy has traditionally taken the form of prosecut- ing persons and corporations who engage in price fixing or market divi- sion, or who obtain or maintain monopoly power by means of abusive practices. More recently, the Antitrust Division, while continuing its attack on private restraints, has opened a second front by seeking to narrow the scope of, or to abolish government regulations which em- body or facilitate restrictions on competition
Nonperturbative Light-Front QCD
In this work the determination of low-energy bound states in Quantum
Chromodynamics is recast so that it is linked to a weak-coupling problem. This
allows one to approach the solution with the same techniques which solve
Quantum Electrodynamics: namely, a combination of weak-coupling diagrams and
many-body quantum mechanics. The key to eliminating necessarily nonperturbative
effects is the use of a bare Hamiltonian in which quarks and gluons have
nonzero constituent masses rather than the zero masses of the current picture.
The use of constituent masses cuts off the growth of the running coupling
constant and makes it possible that the running coupling never leaves the
perturbative domain. For stabilization purposes an artificial potential is
added to the Hamiltonian, but with a coefficient that vanishes at the physical
value of the coupling constant. The weak-coupling approach potentially
reconciles the simplicity of the Constituent Quark Model with the complexities
of Quantum Chromodynamics. The penalty for achieving this perturbative picture
is the necessity of formulating the dynamics of QCD in light-front coordinates
and of dealing with the complexities of renormalization which such a
formulation entails. We describe the renormalization process first using a
qualitative phase space cell analysis, and we then set up a precise similarity
renormalization scheme with cutoffs on constituent momenta and exhibit
calculations to second order. We outline further computations that remain to be
carried out. There is an initial nonperturbative but nonrelativistic
calculation of the hadronic masses that determines the artificial potential,
with binding energies required to be fourth order in the coupling as in QED.
Next there is a calculation of the leading radiative corrections to these
masses, which requires our renormalization program. Then the real struggle of
finding the right extensions to perturbation theory to study the
strong-coupling behavior of bound states can begin.Comment: 56 pages (REVTEX), Report OSU-NT-94-28. (figures not included,
available via anaonymous ftp from pacific.mps.ohio-state.edu in subdirectory
pub/infolight/qcd
Recommended from our members
OER: opening doors and breaching boundaries
The white paper on higher education (BIS, 2011) refers to the government’s social mobility strategy, Opening doors, breaking barriers (HM Government, 2011). The expressed aspirations of the OER (open educational resources) community resonate with the white paper’s three central challenges: attaining sustainability; improving the learner experience; and taking responsibility for social mobility. Lee (2008), writing of the potential of OER, recalls the actions of the eponymous Jude the Obscure, whose anger at exclusion from university led him to graffiti the closed gates of ‘Biblioll College’ (Hardy, 1895). However, while both groups agree that change is necessary, there is little common ground in mapping solutions to opening doors to HE
XR Academia:Research and Experiences in Virtual Reality, Augmented Reality, Mixed Reality, and Artificial Intelligence in Latin America and Europe
The book XR Academia: Research and Experiences in Virtual Reality, Augmented Reality, Mixed Reality, and Artificial Intelligence in Latin America and Europe, has at its core the objective of making immersive technology accessible and visible worldwide, with the simultaneous breaking-down of linguistic barriers. Both European and Latin American authors can read each other’s work(s), allowing knowledge and experience in extended reality to be shared. Another important aspect of XR Academia is its attempt to introduce an open science contribution to the issues of immersive technologies, in order to inspire new generations that do not have access to increasingly expensive publications. This volume includes fourteen selected chapters from presenters from the 2020 and 2021 events. These chapters describe research and experiences on a wide range of XR applications, which include entertainment, health, narration, education, psychotherapy, guidance, language, culture and arts. Considering that great inventions and innovations are developed in Latin America but fail to be published internationally, our aim was to open a door to allow the permanent exchange between two languages: Spanish and English
Coherent Resonant Tunneling Through an Artificial Molecule
Coherent resonant tunneling through an artificial molecule of quantum dots in
an inhomogeneous magnetic field is investigated using an extended Hubbard
model. Both the multiterminal conductance of an array of quantum dots and the
persistent current of a quantum dot molecule embedded in an Aharanov-Bohm ring
are calculated. The conductance and persistent current are calculated
analytically for the case of a double quantum dot and numerically for larger
arrays using a multi-terminal Breit-Wigner type formula, which allows for the
explicit inclusion of inelastic processes. Cotunneling corrections to the
persistent current are also investigated, and it is shown that the sign of the
persistent current on resonance may be used to determine the spin quantum
numbers of the ground state and low-lying excited states of an artificial
molecule. An inhomogeneous magnetic field is found to strongly suppress
transport due to pinning of the spin-density-wave ground state of the system,
and giant magnetoresistance is predicted to result from the ferromagnetic
transition induced by a uniform external magnetic field.Comment: 23 pages, 12 figure
- …