Gravitational cooling of self-gravitating Bose-Condensates

Equilibrium configurations for a self-gravitating scalar field with self-interaction are constructed. The corresponding Schr\"odinger-Poisson (SP) system is solved using finite differences assuming spherical symmetry. It is shown that equilibrium configurations of the SP system are late-time attractor solutions for initially quite arbitrary density profiles, which relax and virialize through the emission of scalar field bursts; a process dubbed gravitational cooling. Among other potential applications, these results indicate that scalar field dark matter models (in its different flavors) tolerate the introduction of a self-interaction term in the SP equations. This study can be useful in exploring models in which dark matter in galaxies is not point-like.Comment: 10 aastex pages, 12 eps figures. Accepted for publication in Ap

Intermolecular N-H...O=C hydrogen bonding in the crystal structure of 6-amino-1,3-dimethyluracil

The 6-amino- 1,3-dimethyluracil molecule [6-amino- 1,3- dimethyl-2,4(1H,3H)-pyrimidinedione], C6H9N302 (I), lies on a crystallographic mirror plane and participates in an extensive two-dimensional hydrogen-bonding network in the solid state. Each molecule is involved in N-- H...O=C hydrogen bonding involving the amino and carbonyl gr. oups, with O...N separations of 2.894 (3) and 2.904 (3) A

Roughness Analysis In Strained Silicon-on-insulator Wires And Films

Strained silicon is used to enhance performance in state-of-the-art CMOS. Under device operating conditions, the effect of strain is to reduce the carrier scattering at the channel by a smoother semiconductor surface. This has never been completely understood. This paper gives first evidence of the variation in surface roughness under realistic strained conditions. At the nanoscale, the SiO2/Si interface roughness is dependent on the scale of observation (self-affinity). To date, there is no experimental study of the SiO2/Si interface roughness scaling with strain. This work presents the effect of uniaxial and biaxial strains on the surface roughness of strained silicon-on-insulator films and wires using atomic force microscopy. Levels of strain ranging from 0% to 2.3%, encompassing those used in present CMOS devices have been investigated. It is shown that the silicon surface is affected by uniaxial and biaxial strains differently. Three surface roughness parameters have been analyzed: root mean square roughness, correlation length, and the Hurst exponent, which is used to describe the scaling behavior of a self-affine surface. The results show that the root mean square roughness decreases (up to ∼ 40%) with increasing tensile strain, whereas the correlation length increases (up to ∼ 63nm/%) with increasing tensile strain. The Hurst exponent also varies with strain and with the undulation wavelength regime (between ∼ 0.8 and 0.2). This dependency explains why some models used to determine the carrier mobility from experiments fit the data better with a Gaussian form, whereas other models fit the data better with an exponential form.11612EPSRC; Engineering and Physical Sciences Research CouncilSong, Y., Zhou, H., Xu, Q., Luo, J., Yin, H., Yan, J., Zhong, H., (2011) J. Electron. Mater., 40, p. 1584Lee, M.L., Fitzgerald, E.A., Bulsara, M.T., Currie, M.T., Lochtefeld, A., (2005) J. Appl. Phys., 97, p. 011101Chu, M., Sun, Y.K., Aghoram, U., Thompson, S.E., (2009) Annu. Rev. Mater. Res., 39, p. 203Zhao, Y., Takenaka, M., Takagi, S., (2009) IEEE Electron Device Lett., 30, p. 987Cheng, Z.Y., Currie, M.T., Leitz, C.W., Taraschi, G., Fitzgerald, E.A., Hoyt, J.L., Antoniadas, D.A., (2001) IEEE Electron Device Lett., 22, p. 321Rim, K., Hoyt, J.L., Gibbons, J.F., (2000) IEEE Trans. Electron Devices, 47, p. 1406Fischetti, M.V., Gamiz, F., Hansch, W., (2002) J. Appl. Phys., 92, p. 7320Bonno, O., Barraud, S., Mariolle, D., Andrieu, F., (2008) J. Appl. Phys., 103, p. 063715Escobedo-Cousin, E., Olsen, S.H., Pardoen, T., Bhaskar, U., Raskin, J.-P., (2011) Appl. Phys. Lett., 99, p. 241906Pirovano, A., Lacaita, A.L., Ghidini, G., Tallarida, G., (2000) IEEE Electron Device Lett., 21, p. 34Goodnick, S.M., Ferry, D.K., Wilmsen, C.W., Liliental, Z., Fathy, D., Krivanek, O.L., (1985) Phys. Rev. B, 32, p. 8171Mazzoni, G., Lacaita, A.L., Perron, L.M., Pirovano, A., (1999) IEEE Trans. Electron Devices, 46, p. 1423Zhao, Y., Matsumoto, H., Sato, T., Koyama, S., Takenaka, M., Takagi, S., (2010) IEEE Trans. Electron Devices, 57, p. 2057Ishihara, T., Matsuzawa, K., Takayanagi, M., Takagi, S.I., (2002) Jpn. J. Appl. Phys., Part 1, 41, p. 2353Pirovano, A., Lacaita, A.L., Zandler, G., Oberhuber, R., Int. Electron Devices Meet. Tech. Dig., 1999, p. 527Yoshinobu, T., Iwamoto, A., Sudoh, K., Iwasaki, H., (1995) J. Vac. Sci. Technol. B, 13, p. 1630Mandelbrot, B.B., (1982) The Fractal Geometry of Nature: Updated and Augment, , (W. H. Freeman and Company)Pelliccione, M., Lu, T.-M., (2007) Evolution of Thin-film Morphology: Modeling and Simulations, , (Springer, Dordrecht)Zhao, Y.P., Wang, G.C., Lu, T.-M., Graef, M.D., Lucatorto, T., (2000) Characterization of Amorphous and Crystalline Rough Surface: Principles and Applications, , (Elsevier Science)Sinha, S.K., Sirota, E.B., Garoff, S., Stanley, H.B., (1988) Phys. Rev. B, 38, p. 2297Stommer, R., Martin, A.R., Geue, T., Goebel, H., Hub, W., Pietsch, U., (1999) Adv. X-Ray Anal., 41, p. 101Vicsek, T., Cserzo, M., Horváth, V.K., (1990) Physica A, 167, p. 315Arnault, J.C., Knoll, A., Smigiel, E., Cornet, A., (2001) Appl. Surf. Sci., 171, p. 189Bhaskar, U.K., Passi, V., Houri, S., Escobedo-Cousin, E., Olsen, S.H., Pardoen, T., Raskin, J.-P., (2012) J. Mater. Res., 27, p. 571Passi, V., Bhaskar, U.K., Pardoen, T., Sodervall, U., Nilsson, B., Petersson, G., Hagberg, M., Raskin, J.P., (2012) J. Microelectromech. Syst., 21, p. 822Bhaskar, U.K., Pardoen, T., Passi, V., Raskin, J.-P., (2013) Appl. Phys. Lett., 102, p. 031911Liu, X.H., Chen, J., Chen, M., Wang, X., (2002) Appl. Surf. Sci., 187, p. 187Vicsek, T., (1992) Fractal Growth Phenomena, , 2nd ed. (World Scientific)Silva, J.B.D., Jr., Vasconcelos, E.A.D., Santos, B.E.C.A.D., Freire, J.A.K., Freire, V.N., Farias, G.A., Silva, E.F.D., Jr., (2005) Microelectron. J., 36, p. 1011Liu, Z.J., Jiang, N., Shen, Y.G., Mai, Y.W., (2002) J. Appl. Phys., 92, p. 3559Gravier, S., Coulombier, M., Safi, A., Andre, N., Boe, A., Raskin, J.-P., Pardoen, T., (2009) J. Microelectromech. Syst., 18, p. 555Bunshah, R.F., (1994) Handbook of Deposition Technologies for Films and Coatings - Science, Technology and Applications, , 2nd ed. (William Andrew Publishing/Noyes)Ureña, F., Olsen, S.H., Šiller, L., Bhaskar, U., Pardoen, T., Raskin, J.-P., (2012) J. Appl. Phys., 112, p. 114506Ureña, F., Olsen, S.H., Raskin, J.-P., (2013) J. Appl. Phys., 114, p. 144507Ghyselen, B., Hartmann, J.M., Ernst, T., Aulnette, C., Osternaud, B., Bogumilowicz, Y., Abbadie, A., Mazure, C., (2004) Solid-State Electron., 48, p. 1285Lai, L., Irene, E.A., (1999) J. Appl. Phys., 86, p. 1729Schwarzenbach, W., Daval, N., Kerdilès, S., Chabanne, G., Figuet, C., Guerroudj, S., Bonnin, O., Maleville, C., (2012) Proceedings of the IEEE International Conference on Integrated Circuit Design and Technology, , (Austin, TX, USA)Xie, Y.H., Gilmer, G.H., Roland, C., Silverman, P.J., Buratto, S.K., Cheng, J.Y., Fitzgerald, E.A., Citrin, P.H., (1994) Phys. Rev. Lett., 73, p. 3006Michielis, M.D., Conzatti, F., Esseni, D., Selmi, L., (2011) IEEE Trans. Electron Devices, 58, p. 321

Galacitic Collapse of Scalar Field Dark Matter

We present a scenario for galaxy formation based on the hypothesis of scalar field dark matter. We interpret galaxy formation through the collapse of a scalar field fluctuation. We find that a cosh potential for the self-interaction of the scalar field provides a reasonable scenario for galactic formation, which is in agreement with cosmological observations and phenomenological studies in galaxies

GDMR A new framework in R to suppot Fuzzy Group Decision Making processes

This is a summary of our article published in Information Science [12] to be part of the MultiConference CAEPIA'15 KeyWorks

Intermediate inflation and the slow-roll approximation

It is shown that spatially homogeneous solutions of the Einstein equations coupled to a nonlinear scalar field and other matter exhibit accelerated expansion at late times for a wide variety of potentials $V$. These potentials are strictly positive but tend to zero at infinity. They satisfy restrictions on $V'/V$ and $V''/V'$ related to the slow-roll approximation. These results generalize Wald's theorem for spacetimes with positive cosmological constant to those with accelerated expansion driven by potentials belonging to a large class.Comment: 19 pages, results unchanged, additional backgroun

The impact of trans-catheter aortic valve replacement induced leftbundle branch block on cardiac reverse remodeling

Background Left bundle branch block (LBBB) is common following trans-catheter aortic valve replacement (TAVR) and has been linked to increased mortality, although whether this is related to less favourable cardiac reverse remodeling is unclear. The aim of the study was to investigate the impact of TAVR induced LBBB on cardiac reverse remodeling. Methods 48 patients undergoing TAVR for severe aortic stenosis were evaluated. 24 patients with new LBBB (LBBB-T) following TAVR were matched with 24 patients with a narrow post-procedure QRS (nQRS). Patients underwent cardiovascular magnetic resonance (CMR) prior to and 6 m post-TAVR. Measured cardiac reverse remodeling parameters included left ventricular (LV) size, ejection fraction (LVEF) and global longitudinal strain (GLS). Inter- and intra-ventricular dyssynchrony were determined using time to peak radial strain derived from CMR Feature Tracking. Results In the LBBB-T group there was an increase in QRS duration from 96 ± 14 to 151 ± 12 ms (P < 0.001) leading to inter- and intra-ventricular dyssynchrony (inter: LBBB-T 130 ± 73 vs nQRS 23 ± 86 ms, p < 0.001; intra: LBBB-T 118 ± 103 vs. nQRS 13 ± 106 ms, p = 0.001). Change in indexed LV end-systolic volume (LVESVi), LVEF and GLS was significantly different between the two groups (LVESVi: nQRS -7.9 ± 14.0 vs. LBBB-T -0.6 ± 10.2 ml/m2, p = 0.02, LVEF: nQRS +4.6 ± 7.8 vs LBBB-T -2.1 ± 6.9%, p = 0.002; GLS: nQRS -2.1 ± 3.6 vs. LBBB-T +0.2 ± 3.2%, p = 0.024). There was a significant correlation between change in QRS and change in LVEF (r = -0.434, p = 0.002) and between change in QRS and change in GLS (r = 0.462, p = 0.001). Post-procedure QRS duration was an independent predictor of change in LVEF and GLS at 6 months. Conclusion TAVR-induced LBBB is associated with less favourable cardiac reverse remodeling at medium term follow up. In view of this, every effort should be made to prevent TAVR-induced LBBB, especially as TAVR is now being extended to a younger, lower risk population

Real-space mapping of tailored sheet and edge plasmons in graphene nanoresonators

Plasmons in graphene nanoresonators have many potential applications in photonics and optoelectronics, including room-temperature infrared and terahertz photodetectors, sensors, reflect arrays or modulators1, 2, 3, 4, 5, 6, 7. The development of efficient devices will critically depend on precise knowledge and control of the plasmonic modes. Here, we use near-field microscopy8, 9, 10, 11 between λ0 = 10–12 μm to excite and image plasmons in tailored disk and rectangular graphene nanoresonators, and observe a rich variety of coexisting Fabry–Perot modes. Disentangling them by a theoretical analysis allows the identification of sheet and edge plasmons, the latter exhibiting mode volumes as small as 10−8λ03. By measuring the dispersion of the edge plasmons we corroborate their superior confinement compared with sheet plasmons, which among others could be applied for efficient 1D coupling of quantum emitters12. Our understanding of graphene plasmon images is a key to unprecedented in-depth analysis and verification of plasmonic functionalities in future flatland technologies.Peer ReviewedPostprint (author's final draft

The Schro¨\ddot{o}dinger-Poisson equations as the large-N limit of the Newtonian N-body system: applications to the large scale dark matter dynamics

In this paper it is argued how the dynamics of the classical Newtonian N-body system can be described in terms of the Schr$\ddot{o}$dinger-Poisson equations in the large $N$ limit. This result is based on the stochastic quantization introduced by Nelson, and on the Calogero conjecture. According to the Calogero conjecture, the emerging effective Planck constant is computed in terms of the parameters of the N-body system as $\hbar \sim M^{5/3} G^{1/2} (N/)^{1/6}$, where is $G$ the gravitational constant, $N$ and $M$ are the number and the mass of the bodies, and $$ is their average density. The relevance of this result in the context of large scale structure formation is discussed. In particular, this finding gives a further argument in support of the validity of the Schr$\ddot{o}$dinger method as numerical double of the N-body simulations of dark matter dynamics at large cosmological scales.Comment: Accepted for publication in the Euro. Phys. J.