Seminars
 
CSIC
25/09/2019 - 00/00/0000
The first image of a black hole
Sala Alberto Lobo (ICE building, UAB Campus)
I will briefly discuss how the first image of a black hole was obtained by the EHT collaboration. In particular, I will describe the theoretical aspects that have allowed us to model the dynamics of the plasma accreting onto the black hole and how such dynamics was used to generate synthetic black-hole images.
UB
19/09/2019 - 00/00/0000
Spin of primordial black holes
Aula 507 (Pere Pascual, ICCUB building, UB Campus)
We discuss the spin of primordial black holes (PBH) formed during radiation domination under the assumption of Gaussian statistics. They are formed by the collapse of rare fluctuations.
CSIC
13/09/2019 - 00/00/0000
Studying the Expansion of the Universe with quasar spectra
Sala Alberto Lobo (ICE building, UAB Campus)
From 2009 to 2014, the Baryon Oscillation Spectroscopic Survey (BOSS) used the SDSS telescope to obtain spectra of 1.5 million galaxies to get very accurate measurements of the Baryon Acoustic Oscillations (BAO) scale at redshift z ~0.5.
UB
13/09/2019 - 00/00/0000
Higher spin motivated theories (of gravity)
Aula 507 (Pere Pascual, ICCUB building, UB Campus)
Despite the continuing efforts, we cannot be truly satisfied with our understanding of the physics in the UV (short distance) limit. The manifestation is that there is no broadly accepted model of quantum gravity.
CSIC
12/07/2019 - 00/00/0000
The 1908 Tunguska Event: 111 years after, it still makes you think
Sala Alberto Lobo (ICE building, UAB Campus)
On June 30th, 1908, an explosion flattened more than two thousands square kilometres of Siberian taigà. During the following 111 years, several theories were proposed to explain the observed features.
UB
04/07/2019 - 00/00/0000
Search optimization and Dynamical Criticality on the String Landscape
Aula 507 (Pere Pascual, ICCUB building, UB Campus)
A striking feature of our universe is its near criticality. The cosmological constant and weak hierarchy problems, as well as the metastability of the electroweak vacuum, can all be understood as problems of criticality. This suggests a statistical physics approach, based on the landscape of string theory.
UB
03/07/2019 - 00/00/0000
Black hole microstate cosmology
Aula 507 (Pere Pascual, ICCUB building, UB Campus)
We consider states of holographic CFTs defined by modifying the standard disk path integral that gives the vacuum state with the insertion of a boundary. We argue that these states correspond to black hole microstates with a geometrical behind-the-horizon region, modelled by a portion of a second asymptotic region terminating at an end-of-the-world (ETW) brane.
CSIC
01/07/2019 - 00/00/0000
Bouncing solutions in modified gravity
L3-03 workshop room (ICE building, UAB Campus)
In this talk, I would like to discuss the modification of general relativity and why we need the modification. Subsequently, I will talk about the bouncing solutions in modified gravity. Bouncing problem is one of the fascinating parts of the study of cosmological dynamics in modified gravity because the big bang singularity could be avoided by a big bounce. The indication of the bouncing universe is: the size of the scale factor contracted to a finite volume.
CSIC
28/06/2019 - 00/00/0000
X-MRIs and IMRIs - From extremely large to intermediate
Sala Alberto Lobo (ICE building, UAB Campus)
The gravitational capture of a compact object by a supermassive black hole is the best probe of strong gravity we have thought of. I will present recent results that predict that such gravitational captures can be detected in the future with space-borne detectors right at our Galactic Centre with extreme signal-to-noise ratios and extremely large mass ratios, via the capture of sub-stellar objects. 
UB
28/06/2019 - 00/00/0000
A primer on Axtronomy
Aula 507 (Pere Pascual, ICCUB building, UB Campus)
We briefly describe the detection of axion dark matter to discuss how an eventual detection can be used to do galactic astronomy and to study the properties of the axionic dark matter halo.
UB
27/06/2019 - 00/00/0000
Spacetimes, symmetries and theories: beyond lorentzian geometry
Aula 507 (Pere Pascual, ICCUB building, UB Campus)
Spacetimes, like Minkowski space, are omnipresent in physics. I will introduce a recent classification of spacetimes that generalizes the classification of maximally symmetric Lorentzian geometries and includes further physically interesting ones.
CSIC
21/06/2019 - 00/00/0000
Simulating Pixels
Sala Alberto Lobo (ICE building, UAB Campus)
Pixel simulations are essential in several phases of a project as they provide mock data that allows us to design, test and optimize the analysis of the images, prior to the real observations. They are also key to evaluate the performance of a survey and help to understand the causes of unknown systematics once the mission starts.  
UB
20/06/2019 - 00/00/0000
Quantum-assisted Machine Learning in Near-Term Quantum Devices
Aula 507 (Pere Pascual, ICCUB building, UB Campus)
With quantum computing technologies nearing the era of commercialization and quantum advantage, machine learning (ML) has been proposed as one of the promising killer applications. Despite significant effort, there has been a disconnect between most quantum ML proposals, the needs of ML practitioners, and the capabilities of near-term quantum devices towards a conclusive demonstration of meaningful quantum advantage in the near future.
UB
20/06/2019 - 00/00/0000
Constraints on the hadron-quark phase transition and the properties of twin stars with GW170817
Aula 507 (Pere Pascual, ICCUB building, UB Campus)
Hybrid stars are compact stars that consist of a core of pure quark or mixed hadron-quark matter and outer layers of hadronic (or nuclear) matter. Depending on its features, the hadron-quark phase transition can lead to a separate mass-radius stable branch of hybrid stars and therefore to "twin-star" solutions, i.e. stars with similar masses and different radii.
UB
20/06/2019 - 00/00/0000
Particle acceleration in protostellar jets: an observational approach
Seminari DAM (724, ICCUB building, UB Campus)
Deeply embedded protostellar jets are well known to be dominated by the emission of thermal electrons. Interestingly, in the last decades, negative spectral indices have been detected at centimeter wavelengths in some protostellar jets, indicating the presence of a non-thermal component. Detecting non-thermal emission implies the existence of relativistic particles interacting with magnetic fields, and therefore, the action of a mechanism able to efficiently accelerate them.
Generalitat de CatalunyaUniversitat de BarcelonaUniversitat Autònoma de BarcelonaUniversitat Politècnica de CatalunyaConsejo Superior de Investigaciones CientíficasCentres de Recerca de Catalunya