About the coordinate time for photons in Lifshitz Space-times

In this paper we studied the behavior of radial photons from the point of view of the coordinate time in (asymptotically) Lifshitz space-times, and we found a generalization to the result reported in previous works by Cruz et. al. [Eur. Phys. J. C {\bf 73}, 7 (2013)], Olivares et. al. [Astrophys. Space Sci. {\bf 347}, 83-89 (2013)], and Olivares et. al. [arXiv: 1306.5285]. We demonstrate that all asymptotically Lifshitz space-times characterized by a lapse funcion $f(r)$ which tends to one when $r\rightarrow \infty$, present the same behavior, in the sense that an external observer will see that photons arrive at spatial infinity in a finite coordinate time. Also, we show that radial photons in the proper system cannot determine the presence of the black hole in the region $r_+<r<\infty$, because the proper time results to be independent of the lapse function $f(r)$.Comment: 5 pages, 4 figures, accepted for publication on EPJ

Endohedral terthiophene in zigzag carbon nanotubes: Density functional calculations

The inclusion and encapsulation of terthiophene (T3) molecules inside zigzag single-walled carbon nanotubes (CNTs) is addressed by density functional calculations. We consider the T3 molecule inside five semiconducting CNTs with diameters ranging from 9.6 to 12.7 Ang. Our results show that the T3 inclusion process is exothermic for CNTs with diameters larger than 9.5 Ang. The highest energy gain is found to be of 2 eV, decreasing as the CNT diameter increases. This notable effect of stabilization is attributed to the positively charged CNT inner space, as induced by its curvature, which is able to accommodate the neutral T3 molecule. The band structure of the T3@CNT system shows that T3 preserves its electronic identity inside the CNTs, superimposing their molecular orbitals onto the empty CNT band structure without hybridization. Our results predict that the electronic states added by the T3 molecules would give rise to optical effects and nonradiative relaxation from excited states.Comment: 5 pages, 5 figures, 1 table, accepted in PR

Structure-activity relationships based on 3D-QSAR CoMFA/CoMSIA and design of aryloxypropanol-amine agonists with selectivity for the human β3-adrenergic receptor and anti-obesity and anti-diabetic profiles

Indexación: Scopus.Acknowledgments: This work was supported by FONDECYT No. 11130701. We would also like to thank fDoTr CthLeafbr efeora vthaeil afrbeilei tayvoafiltahbeilsitoyf towfa trheer seoqfutwireadret orecqaulciureladt etothcealAcuDla(thet ttph:e/ A/dDt c(lhatbt.pw:/e/dbstc.cloabm.w/seobfst.wcoamre/-stoofotlws aarned-tools and http://teqip.jdvu.ac.in/QSAR_Tools/). SDG. Conflicts of Interest: The authors declare no conflict of interest. Conflicts of Interest: The authors declare no conflict of interest.The wide tissue distribution of the adrenergic β3 receptor makes it a potential target for the treatment of multiple pathologies such as diabetes, obesity, depression, overactive bladder (OAB), and cancer. Currently, there is only one drug on the market, mirabegron, approved for the treatment of OAB. In the present study, we have carried out an extensive structure-activity relationship analysis of a series of 41 aryloxypropanolamine compounds based on three-dimensional quantitative structure-activity relationship (3D-QSAR) techniques. This is the first combined comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) study in a series of selective aryloxypropanolamines displaying anti-diabetes and anti-obesity pharmacological profiles. The best CoMFA and CoMSIA models presented values of r2 ncv = 0.993 and 0.984 and values of r2 test = 0.865 and 0.918, respectively. The results obtained were subjected to extensive external validation (q2, r2, r2 m, etc.) and a final series of compounds was designed and their biological activity was predicted (best pEC50 = 8.561). © 2018 by the authors.https://www.mdpi.com/1420-3049/23/5/119

New universality class for the three-dimensional XY model with correlated impurities: Application to 4^4He in aerogels

Encouraged by experiments on $^4$He in aerogels, we confine planar spins in the pores of simulated aerogels (diffusion limited cluster-cluster aggregation) in order to study the effect of quenched disorder on the critical behavior of the three-dimensional XY model. Monte Carlo simulations and finite-size scaling are used to determine critical couplings $K_c$ and exponents. In agreement with experiments, clear evidence of change in the thermal critical exponents $\nu$ and $\alpha$ is found at nonzero volume fractions of impurities. These changes are explained in terms of {\it hidden} long-range correlations within disorder distributions.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let

Three-dimensional track reconstruction for directional Dark Matter detection

Directional detection of Dark Matter is a promising search strategy. However, to perform such detection, a given set of parameters has to be retrieved from the recoiling tracks : direction, sense and position in the detector volume. In order to optimize the track reconstruction and to fully exploit the data of forthcoming directional detectors, we present a likelihood method dedicated to 3D track reconstruction. This new analysis method is applied to the MIMAC detector. It requires a full simulation of track measurements in order to compare real tracks to simulated ones. We conclude that a good spatial resolution can be achieved, i.e. sub-mm in the anode plane and cm along the drift axis. This opens the possibility to perform a fiducialization of directional detectors. The angular resolution is shown to range between 20$^\circ$ to 80$^\circ$, depending on the recoil energy, which is however enough to achieve a high significance discovery of Dark Matter. On the contrary, we show that sense recognition capability of directional detectors depends strongly on the recoil energy and the drift distance, with small efficiency values (50%-70%). We suggest not to consider this information either for exclusion or discovery of Dark Matter for recoils below 100 keV and then to focus on axial directional data.Comment: 27 pages, 20 figure