187 research outputs found
The asymmetry of the dimension 2 gluon condensate: the finite temperature case
In this paper, we continue the work begun in a previous article. We compute,
in the formalism of local composite operators, the value of the asymmetry in
the dimension two condensate for finite temperatures. We find a positive value
for the asymmetry, which disappears when the temperature is increased. We also
compute the value of the full dimension two condensate for higher temperatures,
and we find that it decreases in absolute value, finally disappearing for
sufficiently high temperature. We also comment on the temperature dependence of
the electric and magnetic components of the condensate separately. We compare
our results with the corresponding lattice date found by Chernodub and
Ilgenfritz.Comment: 8 pages, 4 figure
The anomalous dimension of the composite operator A^2 in the Landau gauge
The local composite operator A^2 is analysed in pure Yang-Mills theory in the
Landau gauge within the algebraic renormalization. It is proven that the
anomalous dimension of A^2 is not an independent parameter, being expressed as
a linear combination of the gauge beta function and of the anomalous dimension
of the gauge fields.Comment: 12 pages, LaTeX2e, final version to appear in Phys. Lett.
Community Focused Urban Renewal
Cities across the nation continue to develop and grow,
but in many, rundown industrially zoned lots tend to be
left alone and become an eyesore. These sites need to be
better utilized by the community living around them. There
needs to be a way to develop and design a living community
system integrated into the surrounding city and local
community with the bonus of being semi-self-sufficient.
Combining these new buildings into the existing context
of the urban fabric is essential to any growing city. Urban
redevelopment of a large site within an already growing
city can help to influence further community growth if
done with specific methods.
This thesis seeks to find an architectural solution to
how an urban redevelopment project can renew an area
of a downtown district by creating an integrative living system
into an existing built community. This urban renewal
project consists of utilizing and reusing vacant industrial
land. This architectural framework hopes to reconnect
new integrative communities into their existing urban fabric
while starting and integrating into their own
The effects of Gribov copies in 2D gauge theories
In previous works, we have shown that the Gribov-Zwanziger action, which
implements the restriction of the domain of integration in the path integral to
the Gribov region, generates extra dynamical effects which influence the
infrared behaviour of the gluon and ghost propagator in SU(N) Yang-Mills gauge
theories. The latter are in good agreement with the most recent lattice data
obtained at large volumes, both in 4D and in 3D. More precisely, the gluon
propagator is suppressed and does not vanish at zero momentum, while the ghost
propagator keeps a 1/p^2 behaviour for p^2\approx0. Instead, in 2D, the lattice
data revealed a vanishing zero momentum gluon propagator and an infrared
enhanced ghost, in support of the usual Gribov-Zwanziger scenario. We will now
show that the 2D version of the Gribov-Zwanziger action still gives results in
qualitative agreement with these lattice data, as the peculiar infrared nature
of 2D gauge theories precludes the analogue of the dynamical effect otherwise
present in 4D and 3D. Simultaneously, we also observe that the Gribov-Zwanziger
restriction serves as an infrared regulating mechanism.Comment: 10 pages, 1 .eps figur
Dynamical mass generation by source inversion: Calculating the mass gap of the Gross-Neveu model
We probe the U(N) Gross-Neveu model with a source-term . We
find an expression for the renormalization scheme and scale invariant source
, as a function of the generated mass gap. The expansion of this
function is organized in such a way that all scheme and scale dependence is
reduced to one single parameter d. We get a non-perturbative mass gap as the
solution of . In one loop we find that any physical choice for d
gives good results for high values of N. In two loops we can determine d
self-consistently by the principle of minimal sensitivity and find remarkably
accurate results for N>2.Comment: 13 pages, 3 figures, added referenc
<i>Psammonema</i> gen. n. and <i>Pseudochromadora</i> Daday, 1889 (Nematoda, Desmodoridae) from sandy sediments of Gazi, Kenya
Three new species (Psammonema ovisetosum gen. et sp. n., Pseudochromadora coomansi sp. n.and Pseudochromadora buccobulbosa sp. n.; including all juvenile stages) belonging to a known and to a new genus of the family Desmodoridae (Nematoda, Desmodoroidea) were found in sandy sediments of the intertidal zone in front of the estuarine mangroves of Gazi, Kenya. Psammonema gen. n. differs from Pseudochromadora Daday, 1889 in shape and number of somatic setae in pharyngeal region, in position and shape of lateral alae, and in the anterior position of the amphids on the head capsule. Comments are given on the ecto-symbiotic organisms, feeding habits of the species and on the ontogenetic transformations of some morphological characters
Remarks on the Gribov horizon and dynamical mass generation in Euclidean Yang-Mills theories
The effect of the dynamical mass generation on the gluon and ghost
propagators in Euclidean Yang-Mills theory in the Landau gauge is analysed
within Zwanziger's local formulation of the Gribov horizon.Comment: Work presented at IX Hadron Physics and VII Relativistic Aspects of
Nuclear Physics, Angra dos Reis, RJ, Brazil, March 28 to April 03, 200
Renormalizability of the local composite operator A^2 in linear covariant gauges
The local composite operator is analysed within the algebraic
renormalization in Yang-Mills theories in linear covariant gauges. We establish
that it is multiplicatively renormalizable to all orders of perturbation
theory. Its anomalous dimension is computed to two-loops in the MSbar scheme.Comment: 10 pages, LaTeX, final version to appear in Phys. Lett.
- …