On the semiclassical mass of S2{\mathbb S}^2-kinks

One-loop mass shifts to the classical masses of stable kinks arising in a massive non-linear ${\mathbb S}^2$-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 $S^2$-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

One-loop surface tensions of (supersymmetric) kink domain walls from dimensional regularization

We consider domain walls obtained by embedding the 1+1-dimensional $\phi^4$-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 25 mm, high values of pH, electric conductivity, organic matter, humic acids and soluble nutrients such as NO3−, SO42−, Ca2+, Mg2+, PO43− 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

Producción CientíficaSeparable 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 Sr2_2FeMoO6_6 perovskites studied by photoemission spectroscopy

We report here on the electronic structure of electron-doped half-metallic ferromagnetic perovskites such Sr$_{2-x}$La$_x$FeMoO$_6$ ($x$=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$_F$) with predominantly (Fe+Mo) t$_{2g}^\downarrow$ character has been evidenced for all samples, irrespectively of the $x$ values investigated. Moreover, we show that the electron doping due to the La substitution provides selectively delocalized carriers to the t$_{2g}^\downarrow$ metallic spin channel. Consequently, a gradual rising of the density of states at the E$_F$ 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$_C$

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