Inflation driven by scalar field with non-minimal kinetic coupling with Higgs and quadratic potentials

We study a scalar field with non-minimal kinetic coupling to itself and to the curvature. The slow rolling conditions allowing an inflationary background have been found. The quadratic and Higgs type potentials have been considered, and the corresponding values for the scalar fields at the end of inflation allows to recover the connection with particle physics.Comment: 16 pages, to appear in JCA

Dark energy from scalar field with Gauss Bonnet and non-minimal kinetic coupling

We study a model of scalar field with a general non-minimal kinetic coupling to itself and to the curvature, and additional coupling to the Gauss Bonnet 4-dimensional invariant. The model presents rich cosmological dynamics and some of its solutions are analyzed. A variety of scalar fields and potentials giving rise to power-law expansion have been found. The dynamical equation of state is studied for two cases, with and without free kinetic term . In both cases phenomenologically acceptable solutions have been found. Some solutions describe essentially dark energy behavior, and and some solutions contain the decelerated and accelerated phases.Comment: 21 page

On the Ricci dark energy model

We study the Ricci dark energy model (RDE) which was introduced as an alternative to the holographic dark energy model. We point out that an accelerating phase of the RDE is that of a constant dark energy model. This implies that the RDE may not be a new model of explaining the present accelerating universe.Comment: 8 page

Age problem in holographic dark energy

We study the age problem of the universe with the holographic DE model introduced in [21], and test the model with some known old high redshift objects (OHRO). The parameters of the model have been constrained using the SNIa, CMB and BAO data set. We found that the age of the old quasar APM 08 279+5255 at z = 3.91 can be described by the model.Comment: 13 page

Reconstructing the potentials for the quintessence and tachyon dark energy, from the holographic principle

We propose an holographic quintessence and tachyon models of dark energy. The correspondence between the quintessence and tachyon energy densities with the holographic density, allows the reconstruction of the potentials and the dynamics for the quintessence and tachyon fields, in flat FRW background. The proposed infrared cut-off for the holographic energy density works for two cases of the constant $\alpha$: for $\alpha<1$ we reconstructed the holographic quintessence model in the region before the $\omega=-1$ crossing for the EoS parameter. The cosmological dynamics for $\alpha>1$ was also reconstructed for the holographic quintessence and tachyon models.Comment: 21 pages, 18 figures, 2 table

Multimodal collaborative workgroup dataset and challenges

© 2017, CEUR-WS. All rights reserved. This work presents a multimodal dataset of 17 workgroup sessions in a collaborative learning activity. Workgroups were conformed of two or three students using a tabletop application in a co-located space. The dataset includes time-synchronized audio, video and tabletop system's logs. Some challenges were identified during the collection of the data, such as audio participation identification, and user traces identification. Future work should explore how to overcome the aforementioned difficulties

A direct and sensitive method for screening fructooligosaccharides-digesting microorganisms useful in food and health science

Short-chain fructooligosaccharides (FOS) stimulate selectively the growth and activity of microorganisms in the colon providing positive health effects and well-being in humans and animals. The lack of accurate isolation methods, however, hampers the possibility of getting new potential fructooligosaccharides (FOS)-fermenting yeast or bacterial strains. A valuable screening procedure to visually detect bacterial and yeast strains able to ferment FOS in liquid or solid rich media supplemented with an innocuous pH indicator is described. Using this assay, 15 FOS-consuming strains isolated from different sources were successfully evaluated to prove the utility of the method. This screening procedure is a new and valuable tool in rapid large-scale detection of potential FOS fermenting-strains useful in food and health science.Key words: FOS-fermenting microorganisms, prebiotics, probiotics, symbiotics

Super-resolution, Extremal Functions and the Condition Number of Vandermonde Matrices

Super-resolution is a fundamental task in imaging, where the goal is to extract fine-grained structure from coarse-grained measurements. Here we are interested in a popular mathematical abstraction of this problem that has been widely studied in the statistics, signal processing and machine learning communities. We exactly resolve the threshold at which noisy super-resolution is possible. In particular, we establish a sharp phase transition for the relationship between the cutoff frequency ($m$) and the separation ($\Delta$). If $m > 1/\Delta + 1$, our estimator converges to the true values at an inverse polynomial rate in terms of the magnitude of the noise. And when $m < (1-\epsilon) /\Delta$ no estimator can distinguish between a particular pair of $\Delta$-separated signals even if the magnitude of the noise is exponentially small. Our results involve making novel connections between {\em extremal functions} and the spectral properties of Vandermonde matrices. We establish a sharp phase transition for their condition number which in turn allows us to give the first noise tolerance bounds for the matrix pencil method. Moreover we show that our methods can be interpreted as giving preconditioners for Vandermonde matrices, and we use this observation to design faster algorithms for super-resolution. We believe that these ideas may have other applications in designing faster algorithms for other basic tasks in signal processing.Comment: 19 page

Is Quantum Einstein Gravity Nonperturbatively Renormalizable?

We find considerable evidence supporting the conjecture that four-dimensional Quantum Einstein Gravity is ``asymptotically safe'' in Weinberg's sense. This would mean that the theory is likely to be nonperturbatively renormalizable and thus could be considered a fundamental (rather than merely effective) theory which is mathematically consistent and predictive down to arbitrarily small length scales. For a truncated version of the exact flow equation of the effective average action we establish the existence of a non-Gaussian renormalization group fixed point which is suitable for the construction of a nonperturbative infinite cutoff-limit. The truncation ansatz includes the Einstein-Hilbert action and a higher derivative term.Comment: 18 pages, latex, 3 figure

1,2-Diphenyl-2-(m-tolylamino)ethanone

The title compound, C21H19NO, belongs to the family of -aminoketones. The structure contains three benzene rings, two of which [the phenyl ring in the 1-position (B) and the methylaniline ring (A)] are nearly coplanar [dihedral angle = 5.4 (1)°], whereas the phenyl ring in the 2-position (C) is nearly normal to them [dihedral angles = 81.8 (1) and 87.0 (1)° for A/C and B/C, respectively]. The conformation of the N-H bond is syn to the C=O bond, favouring the formation of a centrosymmetric dimer of molecules in the crystal structure. The molecular packing is consolidated by this N-HO hydrogen-bonding network.Financial support by the Agencia Española de Cooperación Internacional y Desarrollo (AECID), FEDER funding, the Spanish MICINN (MAT2006–01997 and Factoría de Cristalización Consolider Ingenio 2010) and the Gobierno del Principado de Asturias (PCTI) is acknowledged.Peer Reviewe