J. García-Bellido
A5011635269- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Geophysics and Gravity Measurements
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Scientific Research and Discoveries
- CCD and CMOS Imaging Sensors
- Astronomical Observations and Instrumentation
- Remote Sensing in Agriculture
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Particle physics theoretical and experimental studies
- Relativity and Gravitational Theory
- Gaussian Processes and Bayesian Inference
- Statistical and numerical algorithms
- Calibration and Measurement Techniques
Universidad Autónoma de Madrid
2016-2025
Consejo Superior de Investigaciones Científicas
1993-2025
Instituto de Física Teórica
2023-2025
New York University
2024
University College London
2024
University of Copenhagen
2024
Flatiron Health (United States)
2024
Flatiron Institute
2024
Royal Holloway University of London
2024
University of California, Davis
2024
DESI (Dark Energy Spectroscopic Instrument) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions with wide-area galaxy quasar redshift survey. To trace underlying matter distribution, spectroscopic targets be selected in four classes from imaging data. We measure luminous red galaxies up to $z=1.0$. probe Universe out even higher redshift, target bright [O II] emission line $z=1.7$....
We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 deg$^2$ $griz$ imaging data the first year Dark Energy Survey (DES Y1). combine three two-point functions: (i) cosmic shear correlation function 26 million source galaxies in four redshift bins, (ii) angular autocorrelation 650,000 luminous red five (iii) galaxy-shear cross-correlation positions shears. To demonstrate robustness these results, we use independent pairs...
The Einstein Telescope (ET), a proposed European ground-based gravitational-wave detector of third-generation, is an evolution second-generation detectors such as Advanced LIGO, Virgo, and KAGRA which could be operating in the mid 2030s. ET will explore universe with gravitational waves up to cosmological distances. We discuss its main scientific objectives potential for discoveries astrophysics, cosmology fundamental physics.
We present UV, optical, and NIR photometry of the first electromagnetic counterpart to a gravitational wave source from Advanced LIGO/Virgo, binary neutron star merger GW170817. Our data set extends discovery optical at $0.47$ days $18.5$ post-merger, includes observations with Dark Energy Camera (DECam), Gemini-South/FLAMINGOS-2 (GS/F2), {\it Hubble Space Telescope} ({\it HST}). The spectral energy distribution (SED) inferred this $0.6$ is well described by blackbody model $T\approx 8300$...
We present the first cosmology results from large-scale structure in Dark Energy Survey (DES) spanning 5000 deg$^2$. perform an analysis combining three two-point correlation functions (3$\times$2pt): (i) cosmic shear using 100 million source galaxies, (ii) galaxy clustering, and (iii) cross-correlation of with lens positions. The was designed to mitigate confirmation or observer bias; we describe specific changes made sample following unblinding results. model data within flat $\Lambda$CDM...
This overview paper describes the legacy prospect and discovery potential of Dark Energy Survey (DES) beyond cosmological studies, illustrating it with examples from DES early data.DES is using a wide-field camera (DECam) on 4 m Blanco Telescope in Chile to image 5000 sq deg sky five filters (grizY).
We investigate the recently proposed hybrid inflation models with two stages of inflation. show that quantum fluctuations at time corresponding to phase transition between inflationary can trigger formation a large number inflating topological defects. In order study density perturbations in these we further develop method calculate system scalar fields. new type be very on scale transition. The resulting inhomogeneties lead copious production black holes. This could an argument against...
Abstract We describe the first public data release of Dark Energy Survey, DES DR1, consisting reduced single-epoch images, co-added source catalogs, and associated products services assembled over 3 yr science operations. DR1 is based on optical/near-infrared imaging from 345 distinct nights (2013 August to 2016 February) by Camera mounted 4 m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. wide-area survey covering ∼5000 deg 2 southern Galactic cap five broad...
We use 26×106 galaxies from the Dark Energy Survey (DES) Year 1 shape catalogs over 1321 deg2 of sky to produce most significant measurement cosmic shear in a galaxy survey date. constrain cosmological parameters both flat ΛCDM and wCDM models, while also varying neutrino mass density. These results are shown be robust using two independent catalogs, photo-z calibration methods, analysis pipelines blind analysis. find 3.5% fractional uncertainty on σ8(Ωm/0.3)0.5=0.782+0.027−0.027 at 68%...
We study the structure of scalar-tensor theories gravity based on derivative couplings between scalar and matter degrees freedom introduced through an effective metric. Such interactions are classified by their tensor into conformal (scalar), disformal (vector), extended (traceless tensor), as well order field. Relations limited to first derivatives field ensure second-order equations motion in Einstein frame hence absence Ostrogradski ghost freedom. The existence a mapping Jordan is not...
We reconsider the old problem of dynamics spontaneous symmetry breaking (SSB) using 3D lattice simulations. develop a theory tachyonic preheating, which occurs due to spinodal instability scalar field. Tachyonic preheating is so efficient that SSB typically completes within single oscillation as field rolls towards minimum its effective potential. show that, contrary previous expectations, in hybrid inflation tachyonic. Our results may also be relevant for formation topological defects and...
Abstract We present the Dark Energy Camera (DECam) discovery of optical counterpart first binary neutron star merger detected through gravitational-wave emission, GW170817. Our observations commenced 10.5 hr post-merger, as soon localization region became accessible from Chile. imaged 70 deg 2 in i and z bands, covering 93% initial integrated probability, to a depth necessary identify likely counterparts (e.g., kilonova). At 11.4 post-merger we bright transient located nucleus NGC 4993 at...
In this paper we present a new scenario where massive primordial black holes (PBHs) are produced from the collapse of large curvature perturbations generated during mild-waterfall phase hybrid inflation. We determine values inflaton potential parameters leading to PBH mass spectrum peaking on planetarylike masses at matter-radiation equality and producing abundances comparable those dark matter today, while power scales probed by cosmic microwave background (CMB) anisotropies agrees with...
We investigate the potential for LISA space-based interferometer to detect stochastic gravitational wave background produced from different mechanisms during inflation. Focusing on well-motivated scenarios, we study resulting contributions particle production inflation, inflationary spectator fields with varying speed of sound, effective field theories inflation specific patterns symmetry breaking and models leading formation primordial black holes. The projected sensitivities are used in a...
Euclid is a space-based survey mission from the European Space Agency designed to understand origin of Universe's accelerating expansion. It will use cosmological probes investigate nature dark energy, matter and gravity by tracking their observational signatures on geometry universe cosmic history structure formation. The optimised for two independent primary probes: Weak gravitational Lensing (WL) Baryonic Acoustic Oscillations (BAO). payload consists 1.2 m Korsch telescope provide large...
We study the details of preheating in an inflationary scenario which standard model Higgs, strongly nonminimally coupled to gravity, plays role inflaton. find that Universe does not reheat immediately through perturbative decays, but rather initiates a complex process and nonperturbative effects are mixed. The Higgs condensate starts oscillating around minimum its potential, producing $W$ $Z$ gauge bosons nonperturbatively, due violation so-called adiabaticity condition. However, during each...
The grand challenges of contemporary fundamental physics---dark matter, dark energy, vacuum inflation and early universe cosmology, singularities the hierarchy problem---all involve gravity as a key component. And all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some most remarkable predictions General Relativity: event horizons, ergoregions. hitherto invisible landscape Universe is being unveiled before our eyes: historical direct detection...
Primordial Black Holes (PBH) could be the cold dark matter of universe. They have arisen from large (order one) curvature fluctuations produced during inflation that reentered horizon in radiation era. At reentry, these source gravitational waves (GW) via second order anisotropic stresses. These GW, together with those (possibly) sourced by same mechanism responsible for fluctuations, constitute a primordial stochastic GW background (SGWB) unavoidably accompanies PBH formation. We study how...
Primordial Black Holes (PBH) arise naturally from high peaks in the curvature power spectrum of near-inflection-point single-field inflation, and could constitute today dominant component dark matter universe. In this letter we explore possibility that a broad PBH is formed models Critical Higgs Inflation (CHI), where near-inflection point related to critical value RGE running both self-coupling $\lambda(\mu)$ its non-minimal coupling gravity $\xi(\mu)$. We show that, for wide range model...
We combine Dark Energy Survey Year 1 clustering and weak lensing data with Baryon Acoustic Oscillations (BAO) Big Bang Nucleosynthesis (BBN) experiments to constrain the Hubble constant. Assuming a flat $\Lambda$CDM model minimal neutrino mass ($\sum m_\nu = 0.06$ eV) we find $H_0=67.2^{+1.2}_{-1.0}$ km/s/Mpc (68% CL). This result is completely independent of constant measurements based on distance ladder, Cosmic Microwave Background (CMB) anisotropies (both temperature polarization), strong...
We describe the creation, content, and validation of Dark Energy Survey (DES) internal year-one cosmology data set, Y1A1 GOLD, in support upcoming cosmological analyses. The GOLD set is assembled from multiple epochs DES imaging consists calibrated photometric zeropoints, object catalogs, ancillary products - e.g., maps survey depth observing conditions, star-galaxy classification, redshift estimates that are necessary for accurate wide-area catalog ~137 million objects detected coadded...