1,858 research outputs found
Spontaneous Symmetry Breaking at Infinite Momentum without P+ Zero-Modes
The nonrelativistic interpretation of quantum field theory achieved by
quantization in an infinite momentum frame is spoiled by the inclusion of a
mode of the field carrying p+=0. We therefore explore the viability of doing
without such a mode in the context of spontaneous symmetry breaking (SSB),
where its presence would seem to be most needed. We show that the physics of
SSB in scalar quantum field theory in 1+1 space-time dimensions is accurately
described without a zero-mode.Comment: LaTeX, 8 pages, 3 eps figure
The Outburst of the Blazar AO 0235+164 in 2006 December: Shock-in-Jet Interpretation
We present the results of polarimetric ( band) and multicolor photometric
() observations of the blazar AO 0235+16 during an outburst in 2006
December. The data reveal a short timescale of variability (several hours),
which increases from optical to near-IR wavelengths; even shorter variations
are detected in polarization. The flux density correlates with the degree of
polarization, and at maximum degree of polarization the electric vector tends
to align with the parsec-scale jet direction. We find that a variable component
with a steady power-law spectral energy distribution and very high optical
polarization (30-50%) is responsible for the variability. We interpret these
properties of the blazar withina model of a transverse shock propagating down
the jet. In this case a small change in the viewing angle of the jet, by
, and a decrease in the shocked plasma compression by a factor of
1.5 are sufficient to account for the variability.Comment: 22 pages, 8 figures, accepted for Ap
Kiwi talent flow : a study of chartered accountants and business professionals overseas
New Zealanders have always had a propensity to travel overseas. The globalisation of the
world has seen an increase in the number of people who, having completed their education and
gained some work experience, set off on their overseas experience. Concern has been
expressed as to the potential âbrain drainâ that would result should these well-educated and
talented citizens remain overseas permanently. This research considers the propensity to
return of over 1,500 expatriate Kiwis working in the areas of accounting and finance. It
examines their demographics, attitudes, values, motivations, factors of attraction to, and
repulsion from, New Zealand and their concerns for change in New Zealand. It therefore
provides insights into the nature and purpose of this significant group of professionals resident
mainly in the United Kingdom and Australia. We find that less than half are likely to return to
New Zealand. This is because of the lack of career and business opportunities despite the
âpullâ of family and relations in New Zealand
Small x divergences in the Similarity RG approach to LF QCD
We study small x divergences in boost invariant similarity renormalization
group approach to light-front QCD in a heavy quark-antiquark state. With the
boost invariance maintained, the infrared divergences do not cancel out in the
physical states, contrary to previous studies where boost invariance was
violated by a choice of a renormalization scale. This may be an indication that
the zero mode, or nontrivial light-cone vacuum structure, might be important
for recovering full Lorentz invariance.Comment: 23 pgs, 1 fig. Revised for publication: typos corrected, improved
discussion of regularizatio
Fine-Tuning Renormalization and Two-particle States in Nonrelativistic Four-fermion Model
Various exact solutions of two-particle eigenvalue problems for
nonrelativistic contact four-fermion current-current interaction are obtained.
Specifics of Goldstone mode is investigated. The connection between a
renormalization procedure and construction of self-adjoint extensions is
revealed.Comment: 13 pages, LaTex, no figures, to be published in IJMP
Renormalization in Quantum Mechanics
We implement the concept of Wilson renormalization in the context of simple
quantum mechanical systems. The attractive inverse square potential leads to a
\b function with a nontrivial ultraviolet stable fixed point and the Hulthen
potential exhibits the crossover phenomenon. We also discuss the implementation
of the Wilson scheme in the broader context of one dimensional potential
problems. The possibility of an analogue of Zamolodchikov's function in
these systems is also discussed.Comment: 16 pages, UR-1310, ER-40685-760. (Additional references included.
From Free Fields to AdS -- II
We continue with the program of hep-th/0308184 to implement open-closed
string duality on free gauge field theory (in the large limit). In this
paper we consider correlators such as \la \prod_{i=1}^n
\Tr\Phi^{J_i}(x_i)\ra. The Schwinger parametrisation of this -point
function exhibits a partial gluing up into a set of basic skeleton graphs. We
argue that the moduli space of the planar skeleton graphs is exactly the same
as the moduli space of genus zero Riemann surfaces with holes. In other
words, we can explicitly rewrite the -point (planar) free field correlator
as an integral over the moduli space of a sphere with holes. A preliminary
study of the integrand also indicates compatibility with a string theory on
. The details of our argument are quite insensitive to the specific form
of the operators and generalise to diagrams of higher genus as well. We take
this as evidence of the field theory's ability to reorganise itself into a
string theory.Comment: 26 pages, 2 figures; v2. some additional comments, references adde
Three-particle States in Nonrelativistic Four-fermion Model
On a nonrelativistic contact four-fermion model we have shown that the simple
Lambda-cut-off prescription together with definite fine-tuning of the Lambda
dependency of "bare"quantities lead to self-adjoint semi-bounded Hamiltonian in
one-, two- and three-particle sectors. The fixed self-adjoint extension and
exact solutions in two-particle sector completely define three-particle
problem. The renormalized Faddeev equations for the bound states with Fredholm
properties are obtained and analyzed.Comment: 9 pages, LaTex, no figure
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