4,298 research outputs found
Circular 21
Developed from the hybrid Diamond x Khogot by the
Alaska Agricultural Experiment Station, Gasser wheat was
released to seed producers in 1955. This variety exhibits an
excellent combination of high yield and agronomic desirability
m Alaska. It is superior to the standard variety Khogot in
lodging resistance, shattering resistance, and grain quality.
Gasser wheat is not satisfactory for commercial milling and
baking. Its chief value in Alaska will be as a feed for poultry
and livestock.
Gasser is recommended for production in the Matanuska
and Tanana Valleys when a wheat crop is desired. Later maturing
than other cereals, Gasser must be planted early to insure
maturity during the short growing season. Cultural recommendations
are the same as for other cereals.In cooperation with the United States Department of Agricultur
Photon Radiation in a Heat Bath
We discuss the bremsstrahlung of photons into a heat bath, and calculate from
first principles the energy radiated. Even to lowest order the spectrum of the
radiation at low frequency is no more singular than at zero temperature. In
addition to the obvious contributions, this spectrum includes terms associated
with fluctuations. [Revised version has additional explanations]Comment: 7 pages, plus 2 figures in pictex DAMTP 94/
High-temperature QCD and the classical Boltzmann equation in curved spacetime
It has been shown that the high-temperature limit of perturbative thermal QCD
is easily obtained from the Boltzmann transport equation for `classical'
coloured particles. We generalize this treatment to curved space-time. We are
thus able to construct the effective stress-energy tensor. We give a
construction for an effective action. As an example of the convenience of the
Boltzmann method, we derive the high-temperature 3-graviton function. We
discuss the static case.Comment: uuencoded gz-compressed .dvi fil
Renormalization of Wilson Operators in Minkowski space
We make some comments on the renormalization of Wilson operators (not just
vacuum -expectation values of Wilson operators), and the features which arise
in Minkowski space. If the Wilson loop contains a straight light-like segment,
charge renormalization does not work in a simple graph-by-graph way; but does
work when certain graphs are added together. We also verify that, in a simple
example of a smooth loop in Minkowski space, the existence of pairs of points
which are light-like separated does not cause any extra divergences.Comment: plain tex, 8 pages, 5 figures not include
The energy of the high-temperature quark-gluon plasma
For the quark-gluon plasma, an energy-momentum tensor is found corresponding
to the high-temperature Braaten-Pisarski effective action. The tensor is found
by considering the interaction of the plasma with a weak gravitational field
and the positivity of the energy is studied. In addition, the complete
effective action in curved spacetime is written down.Comment: 13 pages, one figure, plain TeX forma
Distribution functions for hard thermal particles in QCD
We find a closed-form for the distribution function (defined in terms of a
Wigner operator) for hot coloured particles in a background gluon field, in the
hard thermal loop approximation. We verify that the current is the same as that
derived from the known effective action.Comment: 12 page
Many-Electron Systems with Constrained Current
A formulation for transport in an inhomogeneous, interacting electron gas is
described. Electronic current is induced by a constraint condition imposed as a
vector Lagrange multiplier. Constrained minimization of the total energy
functional on the manifold of an arbitrary constant current leads to a
many-electron Schroedinger equation with a complex, momentum-dependent
potential. Constant current Hartree-Fock and Kohn-Sham approximations are
formulated within the method and application to transport for quantum wires is
developed. No appeal is made to near equilibrium conditions or other
approximations allowing development of a general ab initio electronic transport
formulation
QCD effective action with dressing functions - consistency checks in the perturbative regime
In a previous paper, we presented solution to the Slavnov--Taylor identity
for the QCD effective action, and argued that the action terms containing
(anti)ghost fields are unique. These terms have the same form as those in the
classical action, but the gluon and (anti)ghost effective fields are convoluted
with gluon and ghost dressing functions G_A and G_c, the latter containing
perturbative and nonperturbative effects (but not including the soliton-like
vacuum effects). In the present work we show how the perturbative QCD (pQCD)
can be incorporated into the framework of this action, and we present explicit
one-loop pQCD expressions for G_A and G_c. We then go on to check the
consistency of the obtained results by considering an antighost
Dyson--Schwinger equation (DSE). By solving the relations that result from the
Legendre transformation leading to the effective action, we obtain the
effective fields as power expansions of sources. We check explicitly that the
aforementioned one-loop functions G_A and G_c fulfil the antighost DSE at the
linear source level. We further explicitly check that these one-loop G_A and
G_c have the regularization-scale and momentum dependence consistent with the
antighost DSE at the quadratic source level. These checks suggest that the the
effective action with dressing functions represents a consistent framework for
treating QCD, at least at the one-loop level.Comment: 17 pages, revtex4; dimensional regularization used instead of
Pauli-Villars, the check of identity in the linear-in-sources Dyson-Schwinger
equation now includes the finite part; conclusions unchanged; to appear in
Phys.Rev.
Computational Stylometry: An Interdisciplinary Project
This project was an analysis of a writers word usage and writing tendencies which, allows a person to recognize a piece of work with out knowing who wrote it and make a reasonable guess about whose work it is
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