304 research outputs found
On the semiclassical mass of -kinks
One-loop mass shifts to the classical masses of stable kinks arising in a
massive non-linear -sigma model are computed. Ultraviolet
divergences are controlled using the heat kernel/zeta function regularization
method. A comparison between the results achieved from exact and
high-temperature asymptotic heat traces is analyzed in depth.Comment: RevTex file, 15 pages, 2 figures. Version to appear in Journal of
Physics
On domain walls in a Ginzburg-Landau non-linear S^2-sigma model
The domain wall solutions of a Ginzburg-Landau non-linear -sigma hybrid
model are unveiled. There are three types of basic topological walls and two
types of degenerate families of composite - one topological, the other
non-topological- walls. The domain wall solutions are identified as the finite
action trajectories (in infinite time) of a related mechanical system that is
Hamilton-Jacobi separable in sphero-conical coordinates. The physical and
mathematical features of these domain walls are thoroughly discussed.Comment: 26 pages, 18 figure
Bases epistemolĂłgicas y operativas de la didĂĄctica del resumen documental: un enfoque basado en la competencia resumidora
Dissecting zero modes and bound states on BPS vortices in Ginzburg-Landau superconductors
One-loop surface tensions of (supersymmetric) kink domain walls from dimensional regularization
We consider domain walls obtained by embedding the 1+1-dimensional
-kink in higher dimensions. We show that a suitably adapted dimensional
regularization method avoids the intricacies found in other regularization
schemes in both supersymmetric and non-supersymmetric theories. This method
allows us to calculate the one-loop quantum mass of kinks and surface tensions
of kink domain walls in a very simple manner, yielding a compact d-dimensional
formula which reproduces many of the previous results in the literature. Among
the new results is the nontrivial one-loop correction to the surface tension of
a 2+1 dimensional N=1 supersymmetric kink domain wall with chiral domain-wall
fermions.Comment: 23 pages, LATeX; v2: 25 pages, 2 references added, extended
discussion of renormalization schemes which dispels apparent contradiction
with previous result
New uses of treated urban waste digestates on stimulation of hydroponically grown tomato (Solanum lycopersicon L.)
One strategy to re-use solid urban wastes is the production of energy by anaerobic digestion. This process also generates high volume of digestates, which are frequently disposal in landfills. The aim of this work is to assess anaerobic digestates as agricultural inputs. Three different biomethanation wastes from different plants were collected. Firstly, a complete physico-chemical characterization of the wastes was done according to the Spanish regulation, showing that the materials had the 90% of the particles below 25Â mm, high values of pH, electric conductivity, organic matter, humic acids and soluble nutrients such as NO3â, SO42â, Ca2+, Mg2+, PO43â and K+. Total concentrations of heavy metals and microbiological parameters were below the threshold levels allowed for agricultural use. The wastes were then treated with a strong acid and a strong base having two different solutions (ATr and BTr, respectively) which were evaluated as biostimulants for tomato plants in hydroponic culture. Those liquid extracts, ATr and BTr, demonstrated their biostimulant ability towards root system of tomato enhancing the hair root density and plant biometric parameters including plants weight and chlorophyll content. This work demonstrates the re-use feasibility of treated digestates in agriculture as fertilizers and more over as feedstock for biostimulants productio
Brane Structure from a Scalar Field in Warped Spacetime
We deal with scalar field coupled to gravity in five dimensions in warped
geometry. We investigate models described by potentials that drive the system
to support thick brane solutions that engender internal structure. We find
analytical expressions for the brane solutions, and we show that they are all
linearly stable.Comment: 10 pages, 7 eps figures; version to be published in JCA
On the Equivalence Between Type I Liouville Dynamical Systems in the Plane and the Sphere
ProducciĂłn CientĂficaSeparable Hamiltonian systems either in sphero-conical coordinates on an S2 sphere or in elliptic coordinates on a R2 plane are described in a unified way. A back and forth route connecting these Liouville Type I separable systems is unveiled. It is shown how the gnomonic projection and its inverse map allow us to pass from a Liouville Type I separable system with a spherical configuration space
to its Liouville Type I partners where the configuration space is a plane and back. Several selected spherical separable systems and their planar cousins are discussed in a classical context
Curie temperature enhancement of electron doped SrFeMoO perovskites studied by photoemission spectroscopy
We report here on the electronic structure of electron-doped half-metallic
ferromagnetic perovskites such SrLaFeMoO (=0-0.6) as
obtained from high-resolved valence-band photoemission spectroscopy (PES). By
comparing the PES spectra with band structure calculations, a distinctive peak
at the Fermi level (E) with predominantly (Fe+Mo) t
character has been evidenced for all samples, irrespectively of the values
investigated. Moreover, we show that the electron doping due to the La
substitution provides selectively delocalized carriers to the
t metallic spin channel. Consequently, a gradual rising of
the density of states at the E has been observed as a function of the La
doping. By changing the incoming photon energy we have shown that electron
doping mainly rises the density of states of Mo parentage. These findings
provide fundamental clues for understanding the origin of ferromagnetism in
these oxides and shall be of relevance for tailoring oxides having still higher
T
The Moduli Space of BPS Domain Walls
N=2 SQED with several flavors admits multiple, static BPS domain wall
solutions. We determine the explicit two-kink metric and examine the dynamics
of colliding domain walls. The multi-kink metric has a toric Kahler structure
and we reduce the Kahler potential to quadrature. In the second part of this
paper, we consider semi-local vortices compactified on circle. We argue that,
in the presence of a suitable Wilson line, the vortices separate into domain
wall constituents. These play the role of fractional instantons in
two-dimensional gauge theories and sigma-models.Comment: 16 pages, LaTex, 2 figures; factors of zeta corrected, meaning of
cross-terms elucidated, further clarifying comments; (more) references adde
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