202,522 research outputs found
Nonperturbative QCD, gauge-fixing, Gribov copies, and the lattice
Perturbative QCD uses the Faddeev-Popov gauge-fixing procedure, which leads
to ghosts and the local BRST invariance of the gauge-fixed perturbative QCD
action. In the asymptotic regime, where perturbative QCD is relevant, Gribov
copies can be neglected. In the nonperturbative regime, one must adopt either a
nonlocal Gribov-copy free gauge (e.g., Laplacian gauge) or attempt to maintain
local BRST invariance at the expense of admitting Gribov copies. These issues
are explored. In addition, we discuss the relationship between recent
Dyson-Schwinger based model calculations of the infrared behavior of QCD
Green's functions and the lattice calculation of these quantities.Comment: 9 pages, 2 figures, to appear in Prog. Theor. Phys. Suppl. in the
proceedings of the Tokyo-Adelaide Joint Workshop on Quarks, Astrophysics and
Space Physic
Medical Marijuana and Pharmacy Practice
By way of the Compassionate Care Act of 2014, New York has become the 23rd state to create a process that will permit patients suffering from a “serious condition” to receive medical marijuana (or “cannabis”). Among those, it is the second state to prohibit the crude delivery system of smoking (Minnesota), and the third to involve pharmacists in the dispensing process (Connecticut and Minnesota). Because virtually every practicing pharmacist in New York will be caring for patients receiving some form of cannabinoid therapy, it is important to discuss the basic outlines established by the law and regulations
Relativistic Space-Times Having Corresponding Geodesics Final Report
Relativistic space-times having corresponding geodesics, classified according to Segre characteristic
The Tits alternative for generalized triangle groups of type (3, 4, 2)
A generalized triangle group is a group that can be presented in the form G = h x, y | xp = yq = w(x, y)r = 1 i where p, q, r ? 2 and w(x, y) is a cyclically reduced word of length at least 2 in the free product Zp ? Zq = h x, y | xp = yq = 1i. Rosenberger has conjectured that every generalized triangle group G satisfies the Tits alternative. It is known that the conjecture holds except possibly when the triple (p, q, r) is one of (2, 3, 2), (2, 4, 2), (2, 5, 2), (3, 3, 2), (3, 4, 2), or (3, 5, 2). Building on a result of Benyash-Krivets and Barkovich from this journal, we show that the Tits alternative holds in the case (p, q, r) = (3, 4, 2)
Bird Migration Through A Mountain Pass Studied With High Resolution Radar, Ceilometers, And Census
Autumnal migration was studied with high-resolution radar, ceilometer, and daily census in the area of Franconia Notch, a major pass in the northern Appalachian Mountains. Under synoptic conditions favorable for migration, broadfront movements of migrants toward the south passed over the mountains, often above a temperature inversion. Birds at lower elevations appeared to be influenced by local topography. Birds moving southwest were concentrated along the face of the mountain range. Birds appeared to deviate their flights to follow local topography through the pass. Specific migratory behavior was not associated with species or species groups. Under synoptic conditions unfavorable for southward migration, multimodal movements probably associated with local flights were as dense as the southward migrations described above. Avian migrants reacting to local terrain may result in concentrations of migrants over ridge summits or other topographic features
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