Finalized PhD theses

Nombre d'entrades: 84

Thermal Diagnostics Experiments for LISA Pathfinder

Estat: defended (23/02/2016)
Estudiant: Ferran Gibert Gutiérrez
Supervisat per: Miquel Nofrarias Serra
Universitat: Universitat Politècnica de Catalunya

The LISA Pathfinder project is an ESA/NASA technology demonstrator mission that must test the critical instrumentation required for a future space-borne gravitational wave observatory based on the LISA design. The satellite, to be launched by the end of 2015, carries two free-floating test masses and…
Estat: defended (23/02/2016)
Estudiant: Ferran Gibert Gutiérrez
Supervisat per: Miquel Nofrarias Serra
Universitat: Universitat Politècnica de Catalunya

The LISA Pathfinder project is an ESA/NASA technology demonstrator mission that must test the critical instrumentation required for a future space-borne gravitational wave observatory based on the LISA design. The satellite, to be launched by the end of 2015, carries two free-floating test masses and an interferometer that measures the relative distance between them. The main objective of the satellite is to demonstrate that the residual acceleration noise between the masses is lower than 3e-14 m/s2/sqrt(Hz) in the band between 1-30 mHz. To achieve such a high sensitivity, the instrument is provided with an accurate control system that allows to sense and actuate on any of the 18 degrees of freedom of the system composed of the two test masses and the spacecraft, avoiding interfering the scientific measurements. The whole instrument is called the LISA Technology Package (LTP). At such low frequencies, the system is exposed to a broad list of external perturbations that eventually limit the sensitivity of the instrument. Amongst them, temperature fluctuations at different spots of the satellite can end up distorting the motion of the masses and the interferometer readouts through different mechanisms. In order to measure such fluctuations and to characterise their contribution to the system sensitivity, the satellite is equipped with a thermal diagnostic subsystem composed of a series of heaters and high precision temperature sensors. Three different kind of thermal perturbation mechanisms are to be studied with such a subsystem: (1) thermal effects inducing direct forces and torques to the test masses due to the presence of temperature gradients, (2) thermo-elastic distortion due to temperature fluctuations in the structure hosting the test masses and the interferometer and (3) thermo-optical distortion of two optical parts located outside the ultra-stabl e optical bench. This thesis focuses on the design of the experiments aimed to study the first two mechanisms. These experiments essentially consist in the injection of a series of heat loads near each of the thermal-sensitive locations in order to stress their associated thermal mechanism. Such an induced perturbation is visible with high SNR at both the optical measurements and the nearby temperature sensors, and allows to derive coupling coefficients for each of the effects or, at least, bound their contribution to the acceleration noise. The analysis of the impact of forces and torques on the test masses has followed two approaches: first, a simulator environment has been designed and implemented to estimate the impact of any kind of heat signal applied close to the test masses and, secondly, a test campaign has been carried out by means of a LTP-test mass replica installed in a torsion pendulum facility. Regarding the simulator, a state-space model has been developed including a thermal system of the whole spacecraft and a specific design for each of the mechanisms that generate forces and torques from temperature gradients: the radiometer effect, the radiation pressure effect and asymmetric outgassing. This model has been integrated to a general simulator of the whole LTP performance, what has allowed to simulate the whole chain between the heater activation and the final impact to the closed-loop performance of the LTP. In parallel, the experimental campaign by means of a torsion pendulum facility of the Universi ty of Trento has allowed to characterise the impact of each of the effects in different scenarios of absolute temperature and pressure. On the other hand, the analysis of thermo-elastic noise in the LTP is based on the results obtained during a spacecraft Thermal Vacuum test campaign. In this test, a series of heater activations in the suspension struts that attach the LTP core assembly to the satellite structure allowed to bound the impact of temperature fluctuations at these locations and to characterise the main mechanical distortion mode associated to them.

Design and Assessment of a low-frequency magnetic measurement system for eLISA

Estat: defended (27/11/2015)
Estudiant: Ignacio Mateos
Supervisat per: José Alberto Lobo Gutiérrez; Juan Ramos (UPC)
Universitat: Universitat Politècnica de Catalunya

Tesis related to LISA pathfinder
The primary purpose of this thesis is the design, development and validation of a system capable of measuring magnetic fields with low-noise conditions at sub-millihertz frequencies. Such an instrument is conceived as a part of a space mission concept for a gravitational-wave observatory called eLISA…
Estat: defended (27/11/2015)
Estudiant: Ignacio Mateos
Supervisat per: José Alberto Lobo Gutiérrez; Juan Ramos (UPC)
Universitat: Universitat Politècnica de Catalunya

The primary purpose of this thesis is the design, development and validation of a system capable of measuring magnetic fields with low-noise conditions at sub-millihertz frequencies. Such an instrument is conceived as a part of a space mission concept for a gravitational-wave observatory called eLISA (evolved Laser Interferometer Space Antenna). In addition, the work of this thesis is also well-suited for use in magnetically sensitive fundamental physics experiments requiring long integration time, such as high-precision measurement of the weak equivalence principle. Within this context, the baseline design of the instrument is also foreseen to monitor the environmental magnetic field in a proposed mission concept involving space atom-interferometric measurements, known as STE-QUEST (Space-Time Explorer and Quantum Equivalence Principle Space Test). Different magnetic sensing technologies (fluxgate, anisotropic magnetoresistance, and atomic magnetometer), together with dedicated electronic noise reduction techniques, are studied in order to assess if they can be used for space missions demanding low-frequency requirements. Moreover, these space missions require the careful control of the local magnetic environment generated by the spacecraft. The reason is that the main on-board instrument can only operate successfully and achieve its performance if the magnetic environment, including that generated by the spacecraft itself, is sufficiently benign.  Therefore, this work also involves the investigation of the magnetic characteristics of the magnetometer and its possible impact on the scientific experiment. Finally, another potential problem is  the accuracy of the magnetic field estimation from the magnetometer to the region of interest.  A robust interpolation method based on an new magnetometer array configuration is presented in this work. Although other topics are covered, the objectives mentioned here are the main issues considered in this thesis.

Cosmology with Galaxy Clustering

Estat: defended (11/06/2015)
Estudiant: Kai Hoffmann
Supervisat per: Enrique Gaztañaga
Universitat: Universitat Autònoma de Barcelona

One of the fundamental goals of Cosmology is to understand how the Universe evolved from initial density fluctuations to the large-scale structure of galaxies which is observed today as the cosmic web. Cosmological models can predict the properties of this structure for a given decomposition of the universal energy into matter and the acceleration of the cosmic expansion. While the major part of matter is believed to consist of an unknown and invisible type of particles, the observed galaxies are assumed to be biased tracers of the total matter distribution. A detailed understanding of galaxy bias is necessary for constraining cosmological models by comparing their predictions to observations. In this thesis galaxy bias will be studied using observational and simulated data. As a first step different methods for measuring the bias will be investigated. For this purpose the bias will be derived from the MICE Simulation and the Millennium Simulation using two- and three-point correlation functions. This results will be compared to direct determinations of the bias from the density contrast. The analysis will be performed for different scales, mass ranges and redshifts. Furthermore the three-point correlation function will be used to test the local model for bias. Deviations of the measurements from the local model predictions will be studied for different cluster shapes. As a second step the dependence of galaxy bias on galaxy properties such as spectral type, color, morphology, magnitude and spatial environment will be investigated. For this purpose mock galaxy catalogs will be used, including semi-analytic models that are imposed on the Millennium Simulation and halo occupation models from the MICE simulation. The properties of the mock galaxies will be compared to observational data such as PAU and SDSS. These studies will provide a base for further investigations of galaxy bias derived from weak lensing observables and redshift space distortions.
For constraining cosmological models via the growth of large-scale matter fluctuations it is important to understand how the observed galaxies trace the full matter density field. The relation between the density fields of matter and galaxies is often approximated by a second- order expansion of…
Estat: defended (11/06/2015)
Estudiant: Kai Hoffmann
Supervisat per: Enrique Gaztañaga
Universitat: Universitat Autònoma de Barcelona

For constraining cosmological models via the growth of large-scale matter fluctuations it is important to understand how the observed galaxies trace the full matter density field. The relation between the density fields of matter and galaxies is often approximated by a second- order expansion of a so-called bias function. The freedom of the parameters in the bias function weakens cosmological constraints from observations. In this thesis we study two methods for determining the bias parameters independently from the growth. Our analysis is based on the matter field from the large MICE Grand Challenge simulation. Haloes, identified in this simulation, are associated with galaxies. The first method is to measure the bias parameters directly from third-order statistics of the halo and matter distributions. The second method is to predict them from the abundance of haloes as a function of halo mass (hereafter referred to as mass function). Our bias estimations from third-order statistics are based on three-point auto- and cross- correlations of halo and matter density fields in three dimensional configuration space. Using three-point auto-correlations and a local quadratic bias model we find a ∼ 20% overestimation of the linear bias parameter with respect to the reference from two-point correlations. This deviation can originate from ignoring non-local and higher-order contributions to the bias function, as well as from systematics in the measurements. The effect of such inaccuracies in the bias estimations on growth measurements are comparable with errors in our measure- ments, coming from sampling variance and noise. We also present a new method for measuring the growth which does not require a model for the dark matter three-point correlation. Res- ults from both approaches are in good agreement with predictions. By combining three-point auto- and cross-correlations one can either measure the linear bias without being affected by quadratic (local or non-local) terms in the bias functions or one can isolate such terms and compare them to predictions. Our linear bias measurements from such combinations are in very good agreement with the reference linear bias. The comparison of the non-local contributions with predictions reveals a strong scale dependence of the measurements with significant deviations from the predictions, even at very large scales. Our second approach for obtaining the bias parameters are predictions derived from the mass function via the peak-background split approach. We find significant 5−10% deviations between these predictions and the reference from two-point clustering. These deviations can only partly be explained with systematics affecting the bias predictions, coming from the halo mass function binning, the mass function error estimation and the mass function parameterisation from which the bias predictions are derived. Studying the mass function we find unifying relations between different mass function parameterisation. Furthermore, we find that the standard Jack-Knife method overestimates the mass function error covariance in the low mass range. We explain these deviations and present a new improved covariance estimator.

Bayesian data analysis for LISA Pathfinder. Techniques applied to system identificaction experiments.

Estat: defended (13/01/2015)
Estudiant: Nikolaos Karnesis
Supervisat per: Carlos Sopuerta ; Miquel Nofrarias Serra
Universitat: Universitat Autònoma de Barcelona

LISA is a joint mission between the European Space Agency (ESA) and the US National Aeronautics and Space Administration (NASA) that will become the first space-based Gravitational-Wave (GW) detector. LISA is a constellation of three spacecrafts that will access GW signals at frequencies of 1mHz and below, around five orders of magnitude below the kHz band where Earth-based detectors, such as VIRGO and LIGO operate. LISA will open a new window to the observation of the Universe and is expected to provide revolutionary discoveries in the areas of Astrophysics, Cosmology, and Fundamental Physics. Due to the technological complexity of LISA, ESA approved a percursor mission, LISA PathFinder (LPF), to test the readiness of the main LISA technology. The scientific working principle of LISA is the detection of tiny relative displacements between pairs of proof masses in nominally geodesic motion, or free fall, induced by passing GWs. LPF consists in a single spacecraft hosting two proof masses in nominal free fall, whose motions are monitored by means of a Mach-Zender laser interferometer. LPF is expected to be launched around 2012 and its ultimate objective is to measure the noise in the proof masses motion, and to understand its physical origin. There are many sources of noise identified (thermal, magnetic, particles of cosmic origin, etc), and properly modelling them requires a careful planning of the measurement sequence, plus of course the use of suitable analysis tools to process the various data channels. The research work proposed for this PhD project consists of the following three points: 1. Development of Data Analysis Tools for the LTPDA software tool in order to perform the Data Analysis during the mission operations and also for the scientific parts that will be carried out by our Research Group. Also to participate in the Mock Data Analysis challenges organized by the LPF community. 2. To study how to develop a LISA noise model from the outcome of the LPF mission. 3. To develop Data Analysis Tools for LISA, which consists in the detection of GW signals and the estimation of the physical parameters of the associated sources. Also to participate in Mock Data Analysis challenges organized by the LISA scientific community (LISC).
The eLISA concept design consists of a constellation of three space-crafts forming a triangle in the sky. While in a sun centered orbit, it will constantly monitor the distance oscillations between the test bodies enclosed in the different space-crafts. Its principal goal, is to detect oscillations that…
Estat: defended (13/01/2015)
Estudiant: Nikolaos Karnesis
Supervisat per: Carlos Sopuerta ; Miquel Nofrarias Serra
Universitat: Universitat Autònoma de Barcelona

The eLISA concept design consists of a constellation of three space-crafts forming a triangle in the sky. While in a sun centered orbit, it will constantly monitor the distance oscillations between the test bodies enclosed in the different space-crafts. Its principal goal, is to detect oscillations that are caused by passing Gravitational-Waves. The technical complexity of this design was the reason for ESA and NASA to approve the LISA Pathfinder mission (LPF) which aims at testing all the key technologies for future Gravitational-Wave space observatories.
The LISA Technology Package (LTP) instrument onboard the LPF satellite, can be considered as one eLISA arm, squeezed from 1 million km to approximately 30 cm, and it aims to measure the differential acceleration between two test-bodies with unparalleled precision via a Mach-Zehnder interferometer. Among its objectives we have: The estimation of the acceleration noise models, the derivation of an accurate dynamical model of the system in all degrees-of-freedom, and the estimation of the systems’ parameters. In this thesis, we focus on a Bayesian analysis framework to set-up analysis strategies to process the planned system identification experiments.

We first model the system using different approximations, and then we develop and apply Markov Chain Monte Carlo (MCMC) algorithms to simulated data-sets. We report the accuracy on the parameters over the planned system identification experiments, that can be divided in two categories; the x-axis system identification experiments, that are performed over the sensitive axis defined by the line joining the two
test masses; and the so-called cross-talk experiments, where different degrees of freedom of the test bodies of the system are excited. The various cross-coupling physical effects that produce signal leakage on the sensitive differential interferometer channel,are then identified and estimated. In addition, the pipeline analysis designed for on-line
data analysis during operations is presented.

Finally, we also investigate the possible model selection problems in LPF data analysis, and we apply the reversible jump MCMC algorithm to simulated data sets. Different applications to the x-axis and the cross-talk experiments are considered, where the efficiency of the developed tools is demonstrated. We also show the association of
the model selection results to the design of the experiment itself. The above work is integrated to the LTP data analysis dedicated toolbox, the LTPDA. 

Stellar activity in exoplanet hosts

Estat: defended (06/10/2014)
Estudiant: Enrique Herrero Casas
Supervisat per: Ignasi Ribas Canudas
Universitat: Universitat de Barcelona

Stellar activity in exoplanet hosts Most of the efforts on the search and characterization of Earth-like exoplanets are currently focused on low mass stars. Some important properties related to the structure and processes in this type of stars are still unknown, so a careful characterization…
Estat: defended (06/10/2014)
Estudiant: Enrique Herrero Casas
Supervisat per: Ignasi Ribas Canudas
Universitat: Universitat de Barcelona

Stellar activity in exoplanet hosts Most of the efforts on the search and characterization of Earth-like exoplanets are currently focused on low mass stars. Some important properties related to the structure and processes in this type of stars are still unknown, so a careful characterization is essential as one of the next steps in exoplanet sciences. The characterization of stellar activity in low mass stars was carried out through several techniques that allowed us both to model and to simulate the relationships between the observational data and the stellar properties. Several empyrical relations for low mass stars allow to find correlations between certain activity indicators and the rotation period. These have permitted us to generate synthetic samples of stars with stochastic distributions of stellar and geometric properties allowing to estimate the inclination of the rotation axis from the distribution in the activity-vsini diagram. The methodology was applied to a sample of 1200 observed low mass stars and the best candidates for a targeted transit search were selected. Spot modelling techniques allow to obtain physical information about the stellar surface from time series photometric and spectroscopic data. In this work we analyse Kepler photometry of LHS 6343 A, an M-dwarf being eclipsed by a brown dwarf companion every 12.718 days, and showing photometric oscillations with the same periodicity and a phase lag of 100o from the eclipses. The accurate modeling of the Kepler data allowed to explain these oscillations with the presence of active regions appearing at a fixed longitude, thus suggesting a possible magnetic connection between both components. On the other hand, we also studied an alternative explanation for the photometric oscillations in LHS 6343 A in terms of the Doppler beaming effect, showing that this could be the main cause of the observed oscillations. Stellar activity effects are responsible for the noise observed at different amplitude and timescales on time series data. Such noise represents one of the main limitations for exoplanetary sciences. In order to characterize it, we designed a methodology to simulate the photosphere of an active rotating star through the integration of small surface elements from Phoenix atmosphere models. This allows to characterize the signal produced by activity and further study its relationship with the stellar properties, as well as the possible effects produced on exoplanet measurements. The methodology allowed us to present several strategies in order to correct or reduce the effects of spots on the photometry of exoplanet transits, as these may induce significant variations on the measurement of the planetary radius. We focused on a comprehensive analysis of HD 189733, a K5 star hosting a giant planet, which has simultaneous photometric (MOST) and spectroscopic (SOPHIE) data available. An accurate surface map was obtained using the methodology above, accurately reproducing the light curve and radial velocity observations. Such map was used in order to study the effects of activity on the exoplanet transits. We showed that the effects of spot-crossing events are significant even for mid-infrared wavelengths. Moreover, the chromatic effects of spots not occulted by the planet show a signal with a wavelength dependence and amplitude that are very similar to the signature of the atmosphere of a planet dom- inated by dust. The radial velocity theoretical curve is in agreement with the observations up to the typical instrumental systematics of SOPHIE. The results from this work conclude that it is essential to correctly model the stellar activity signals for exoplanetary sciences, and we provide some tools and strategies to characterize and reduce such effects and extract astrophysical information. 

Theory and observations of the PWN-SNR complex

Estat: defended (21/07/2014)
Estudiant: Jonatan Martín Rodríguez
Supervisat per: Diego F. Torres ; Nanda Rea
Universitat: Universitat Autònoma de Barcelona

In this work, we study theoretical and observational issues about pulsars (PSRs), pulsar wind nebulae (PWNe) and supernova remnants (SNRs). In particular, the spectral modeling of young PWNe and the X-ray analysis of SNRs with magnetars comparing their characteristics with those remnants surrounding…
Estat: defended (21/07/2014)
Estudiant: Jonatan Martín Rodríguez
Supervisat per: Diego F. Torres ; Nanda Rea
Universitat: Universitat Autònoma de Barcelona

In this work, we study theoretical and observational issues about pulsars (PSRs), pulsar wind nebulae (PWNe) and supernova remnants (SNRs). In particular, the spectral modeling of young PWNe and the X-ray analysis of SNRs with magnetars comparing their characteristics with those remnants surrounding canonical pulsars. The spectra of PWNe range from radio to $\gamma$-rays. They are the largest class of identified Galactic sources in $\gamma$-rays increasing the number from 1 to $\sim$30 during the last years. We have developed a detailed spectral code which reproduces the electromagnetic spectrum of PWNe in free expansion ($t_{age} \lesssim$10 kyr). We shed light and try to understand issues on time evolution of the spectra, the synchrotron self-Compton dominance in the Crab Nebula, the particle dominance in PWNe detected at TeV energies and how physical parameters constrain the detectability of PWNe at TeV. We make a systematic study of all Galactic, TeV-detected, young PWNe which allows to find correlations and trends between parameters. We also discuss about the spectrum of those PWNe not detected at TeV and if models with low magnetized nebulae can explain the lack of detection or, on the contrary, high-magnetization models are more favorable. Regarding the X-ray analysis of SNRs, we use X-ray spectroscopy in SNRs with magnetars to discuss about the formation mechanism of such extremely magnetized PSRs. The alpha-dynamo mechanism proposed in the 1990's produces an energy release that should have influence in the energy of the SN explosion. We extend the work done previously done by \cite{vink06} about the energetics of the SN explosion looking for this energy release and we look for the element ionization and the X-ray luminosity and we compare our results with other SNRs with an associated central source.

Weak Lensing Analysis of an All-Sky Simulation

Estat: defended (24/01/2014)
Estudiant: Carlos Lopez Arenillas
Supervisat per: Pablo Fosalba Vela; Enrique Gaztañaga
Universitat: Universitat de Barcelona

This Thesis is concerned with one of the most promising probes to constrain the "Dark Universe", and, particularly, the dark matter distribution. Based on MICE cosmological simulation, and the all-sky convergence maps generated by Fosalba, Gaztanaga, Castander & Manera (2003) we perform a mass calibration…
Estat: defended (24/01/2014)
Estudiant: Carlos Lopez Arenillas
Supervisat per: Pablo Fosalba Vela; Enrique Gaztañaga
Universitat: Universitat de Barcelona

This Thesis is concerned with one of the most promising probes to constrain the "Dark Universe", and, particularly, the dark matter distribution. Based on MICE cosmological simulation, and the all-sky convergence maps generated by Fosalba, Gaztanaga, Castander & Manera (2003) we perform a mass calibration of the dark matter halos there contained up to z=1. In order to do that, we analyse the average halo density proÖles of all the halos with masses ranging from 5E13 to 4E14 Msol/h , divided into four mass bins and three redshift bins. Through this analysis we address two main issues: the relatively low mass resolution of the simulation (mp=2.34 1011 h1M ) and the relatively high softening length (lsoft=50 h1 Kpc). We do that by using a two-step procedure. First, we simulate analytical pure NFW density profiles (with di§erent mass resolutions) using two input values: the virial radii of MICE halos and the expected concentrations, according to the Öxed mass-concentration relation from Oguri and Hamana [130]. Second, we model the e§ect of the softening length with a Gaussian Ölter, smoothing the halo core. The results show that MICE halos are, in average, NFW halos. Best-O NFW radii are in very good agreement with the average radii of our samples, overestimating the data by  1%, but best-fit NFW concentrations are in average 50% lower than the expected values. It is possible to account for part of this deviation by distinguishing between relaxed and unrelaxed halos, finding that, depending on the degree of relaxedness, the improvement can be as high as 30%. We also find that the analytical NFW halos simulated with MICE mass resolution have an overall concentration 40% lower than the input concentration, in the case of 3D proÖles, and 25% lower in that of the projected proÖles. The Gaussian-smoothed NFW profile is a good approximation for our projected halos. Additionally, we analyse the morphology of the halos, characterizing their triaxiality at R200 and calculating their orientation with respect to the line-of-sight (LOS). MICE halos tend to adopt a more prolate morphology, as might be expected from a  CDM simulation (Shaw et al. [159]), and the percentage of prolate halos grows as their mass grows. The mass resolution is, nonetheless, not good enough to draw conclusive inferences from the shape analysis, but it allows us to discern a trend and estimate the e§ect of halo shape and orientation on the weak lensing masses. Finally, we use the all-sky convergence maps to study the scatter in mass measurements of MICE halos. We determine the intrinsic scatter in the recovered masses by assuming the smoothed NFW profile as the ìtrueî profile, and creating two new convergence maps from different mass cuts. We estimate also the scatter due to the correlated structure by studying the angles between the major axes of the halos and the LOS, and also that due to projection e§ects (i.e. all the dark matter between observer and source). We find an irreducible scatter (intrinsic) of 10-14%, a scatter around a 30% of the intrinsic one due to correlated structure, and a scatter around 40-70% of the intrinsic one due to projection e§ects. The size of our halo sample allows us to improve the characterization of the cosmic noise, of great importance for present and future surveys.

CROSS-CORRELATING SPECTROSCOPIC AND PHOTOMETRIC GALAXY SURVEYS

Estat: defended (16/01/2014)
Estudiant: Martin B. Eriksen
Supervisat per: Enrique Gaztañaga
Universitat: Universitat Autònoma de Barcelona

CROSS-CORRELATING SPECTROSCOPIC AND PHOTOMETRIC GALAXY SURVEYS
Estat: defended (16/01/2014)
Estudiant: Martin B. Eriksen
Supervisat per: Enrique Gaztañaga
Universitat: Universitat Autònoma de Barcelona

CROSS-CORRELATING SPECTROSCOPIC AND PHOTOMETRIC GALAXY SURVEYS

Dynamically-generated baryon resonances with heavy flavor

Estat: defended (10/01/2014)
Estudiant: Romanets, O. (KVI, University of Groningen)
Supervisat per: Tolos, L.; Timmermans, R. (KVI, University of Groningen)

To study the properties of exotic hadrons with charm and strange content under extreme conditions of density and temperature, with applications for astrophysical observables in neutron stars and supernovae as well as for the future FAIR project at GSI.
Study the properties of dynamically-generated baryon resonaces with strange and charm content
Estat: defended (10/01/2014)
Estudiant: Romanets, O. (KVI, University of Groningen)
Supervisat per: Tolos, L.; Timmermans, R. (KVI, University of Groningen)

Study the properties of dynamically-generated baryon resonaces with strange and charm content

Theories of modified gravity and reconstruction schemes of cosmological models

Estat: defended (08/11/2013)
Estudiant: Antonio Jesús López Revelles
Supervisat per: Emilio Elizalde ; Sergei D Odintsov
Universitat: Universitat de Barcelona

The present thesis, aimed at obtaining the title of Philosophy Doctor in Physics, is based on the following papers published in referred journals, pre-prints and conference proceedings:  S. Capozziello, M. De Laurentis and A. J. Lopez-Revelles. Weak eld limit for F(R; G) modi ed gravities. In preparation. …
Estat: defended (08/11/2013)
Estudiant: Antonio Jesús López Revelles
Supervisat per: Emilio Elizalde ; Sergei D Odintsov
Universitat: Universitat de Barcelona

The present thesis, aimed at obtaining the title of Philosophy Doctor in Physics, is based on the
following papers published in referred journals, pre-prints and conference proceedings:
 S. Capozziello, M. De Laurentis and A. J. Lopez-Revelles. Weak eld limit for F(R; G) modi ed
gravities. In preparation.
 K. Bamba, A. J. Lopez-Revelles, R. Myrzakulov, S. D. Odintsov, and L. Sebastiani. Cosmic history
of viable exponential gravity: Equation of state oscillations and growth index from in
ation to dark
energy era. Class. Quant. Grav. 30:015008 (2013).
 K. Bamba, A. J. Lopez-Revelles, R. Myrzakulov, S. D. Odintsov, and L. Sebastiani. The universe
evolution in exponential F(R) -gravity. Proceedings of QFTG2013, published in TSPU Bulletin 3
(128), 2012, n 13 p.19-24.
 E. Elizalde and A. J. Lopez-Revelles.Reconstructing cosmic acceleration from modi ed and nonmin-
imal gravity: The Yang-Mills case. Phys. Rev. D, 82:063504 (2010).
 E. Elizalde, A. J. Lopez-Revelles, S. D. Odintsov, and S. Yu. Vernov. Cosmological models with
Yang-Mills elds. Phys.Atom.Nucl., 76:996 (2013).
 A. J. Lopez-Revelles. Growth of matter perturbations for realistic F(R) models. Phys. Rev. D,
87:024021 (2013).
 A. J. Lopez-Revelles. Reconstructing cosmic acceleration from f(R) modi ed gravity. Proceedings
of ERE2011, Madrid. ArXiv: 1301.2190.
 A. J. Lopez-Revelles and E. Elizalde. Universal procedure to cure future singularities of dark energy
models. Gen. Rel. Grav., 44:751 (2012).
 A. J. Lopez-Revelles, R. Myrzakulov and D. Saez-Gomez. Ekpyrotic universes in F(R) Horava-
Lifshitz gravity. Phys. Rev. D, 85:103521 (2012).
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