The physicist Roberto Emparan (Bilbao, 1967) is an ICREA researcher lecturer at the University of Barcelona and also member of the Institute of Cosmos Sciences of the UB (ICCUB). His fieldwork is gravitation and cosmology, as well as their most basic objects: black holes. Emparan obtained an Advanced Grant by the European Research Council (ERC) for a project to find new strategies with which study gravity and black holes.

Black holes have a central role in Einstein’s theory of relativity. However, his equations are extremely hard to solve. The project Emparan led aims to develop a new perspective to solve the physics that regulate black holes.

What is the relation between black holes and the theory of relativity?

Black holes are the simplest and most basic objects in which we can see the most relevant aspects of Einstein’s theory, and even though this theory is already a hundred years old, it is rich and complex enough for us so we have not taken everything it offers yet –not only experimentally but also theoretically.

Black holes are a prediction of the theory of relativity which took a long time to be accepted and understood: actually, Einstein never accepted it. What is more, he even wrote some articles denying the possibility of black holes’ existence, although they didn’t have that name then. Einstein died without knowing about the existence of these astronomic objects and not knowing that they showed the most dramatic consequences of his theory.

In what simple way can we understand how black holes behave?

The project I presented is based on an idea we started to elaborate a few years ago. The limit we took to understand black holes better –albeit it seems strange- consists on considering that the number of space dimensions, instead of being the usual one (three spatial and one temporal dimension) is endless. In previous works we realized that, with this idea, black holes get simplified.

Although it looks strange, it is not very different from what we do in physics, for example when we study the launch of a projectile ignoring air resistance.

Physics are the art of making approximations, like the joke about the spherical cow, in which in the first approximation a cow is a sphere to which some details are then added. This allows us simplifying the problem and making corrections.

Therefore, what we found is a way to change the theory of relativity in a way that black holes turn into that kind of spherical cow, and although we simplify its dynamics, we can later calculate properties and make corrections to get closer to their real behaviour.

Another result that was relevant regarding the black holes we saw some years ago is the fact that Einstein’s theories allow us understanding black holes as soap bubbles, since they satisfy the same elastic membrane equations. Specifically, the horizon of the black hole –an area with a complicated dynamic- is what we could see behaving as a soap bubble. Therefore, it is a useful simplification and… the prettiest one!

Does this approximation have consequences on the idea we have about the Universe?

Maybe! It is a mathematic method that allowed us guessing how a black hole works and what its dynamics are. This limit allows us getting the essence of the black hole.

This is a new idea, not inspired on previous advances. The advanced grant our project received will allow us elaborating this idea from a theoretical perspective to know all about of its implications. The project will allow us contracting post-doctoral researchers to elaborate on the theory.

What role do black holes have in the Universe?

We don’t know it for sure, but probably black holes have a more important role. The main thing is that, regarding the theory of gravity, they allow us going further than what Einstein said. For instance, when we try to have quantum mechanics in mind. Einstein’s theory was classy, and Stephen Hawking is the one who introduces quantum mechanics into gravitation.

Beforehand, it seems quite contradictory to introduce quantum mechanics to a gravitation theory.The important effects in quantum theory are very small when in objects of a mass similar to the Sun’s, or of a bigger mass, like black holes; but we think that in the origin of the Universe there could have been some microscopic black holes. In the primitive Universe, temperature and density were much higher and we can introduce the theory of quantum space-time.

Somehow, black holes are physics at its limits.

To what point does the general relativity apply to systems that go further than the common gravitation systems?

This is one of the surprises of Einstein’s theory: it has been proved that the theory of relativity is not only useful to describe the cosmos but also to describe systems without gravity in a subtle way. Just like we use the theory of the soap bubbles to describe black holes making certain assumptions.

This is the case of the experiments that are being carried out on particle accelerators such as LHC, with particle systems that can be described in an easier way –and though it seems strange- as if this plasma was a black hole in a 5-dimension space.

Does this go with the idea that physics are the same at all levels?

Actually, good ideas work in lots of places, and Einstein’s theory of relativity is a very good theory, and it can be applied in lots of systems: with this theory we can understand phenomena related to superconductivity.

Personally, the theory of relativity is the cleverest theory we have, smarter than all of us. Sometimes theories are smarter than their creators, and Einstein’s case is clear: with the expansion of the Universe, with the black holes, his theory was telling him things he didn’t fully accept.

Translation of MINECO Press Release. Their Majesties the King and Queen of Spain have received in the Zarzuela Palace the directors and representatives of 33 centres and units which have been accredited with the highest institutional recognition to the scientific research in Spain, the centres ‘Severo Ochoa’ and the units ‘María de Maeztu’. The event has been presented by the Secretary of State for Research, Development and Innovation, Carmen Vela, who has highlighted the importance of these centres for Spanish Science.

These honours are awarded since 2011 after a rigorous assessment process carried out by international scientific committees grouped into three areas: life sciences and medicine, experimental sciences, mathematics and engineering and social sciences and humanities. The accredited centres and unities stand out both for the international impact of their scientific contributions as for their innovative ability and strong relationship with the social and economic environment. Moreover, they are as well worldwide reference institutions able to attract international talent.

Since 2015 this accreditation was widened with a new modality addressed to research unities called ‘María de Maeztu’, with the aim of recognising the excellence in organized structures of research smaller than centres, mostly located in universities.

The telescopes will form part of the future Cherenkov Telescope Array in the Northern Hemisphere (CTA-North) at the Roque de los Muchachos Observatory

On April 13th, the acting Secretary of State for R+D+i, Carmen Vela, presided, together with the Japanese Deputy Minister of Education, Culture, Sport, Science and Technology, Tsutomu Tomioka, over the signing of the collaborative agreement for the installation and operation of four Cherenkov telescopes at the Roque de los Muchachos Observatory on the Island of La Palma. The agreement was signed in Tokyo by Rafael Rebolo, Director of the Instituto de Astrofísica de Canarias (IAC) and Takaaki Kajita, Director of the Institute for Cosmic Ray Research (ICRR) of the University of Tokyo.

The group of the Institute of Cosmos Sciences (IEEC-UB) led by Josep Maria Paredes and Marc Ribó has participated in the scientific objectives definition and are involved in the design and production microelectronics for CTA cameras.

About CTA

The CTA consortium is made up by over 1,200 scientists working in 200 research centres in 32 countries. Spain and Japan are the two major contributors to CTA-North. The objective of the consortium is to build a telescopic array for the detection of extremely high energy gamma rays which yield information about the most violent extreme events occurring in the universe.

The Ministry of Economy and Competitivity has added its major financial effort to those of other international and national entities to bring the CTA-North to Spain, providing a fund of 40 million euros, which is half the total construction cost.

The CTA is formed by two observatories, one in the northern and the other in the southern hemisphere. The total array will be made up of 120 telescopes, distributed between the two. The CTA-North observatory will be sited at the Roque de los Muchachos Observatory on the Island of La Palma, while CTA-South will be at the Observatory of the European Southern Observatory (ESO), at Cerro Paranal (Chile).

ICREA-ICCUB researcher R. Emparan has been awarded an Advanced Grant by the European Research Council (ERC) for his project A New Strategy for Gravity and Black Holes in the 2015 call. The call received close to 2000 applications. The success rate in this call has not been announced yet, but in the previous call it was only 8.5%. The funding is up to 2.5 million Euros per grant and lasts up to five years.

The ERC Advanced Grants are part of the European Union Research and Innovation programme Horizon 2020. They are designed for established and world leading researchers to pursue ground-breaking, high-risk projects in Europe.

R. Emparan has been ICREA Research Professor at the University of Barcelona since 2003, and a member of ICCUB since its creation in 2006. He carries out research in gravitation and cosmology, trying to understand the nature of spacetime at its most fundamental level. Particularly, he studies the classical and quantum aspects of gravity and its most basic objects: the black holes.

General Relativity — Einstein’s theory of gravity — encompasses a huge variety of physical phenomena and provides the basis to our understanding of the Universe and its evolution at the largest scales. Black holes play a central role in this theory. However, their equations are exceedingly hard to solve. The awarded project led by R. Emparan is aimed at developing a novel approach to solve black hole physics by using the number of dimensions D as a perturbation parameter.

Specifically, the project pursuits two major goals: reformulating General Relativity and Black Hole physics around the large-D limit in terms of an effective membrane theory of black holes, coupled to an effective theory for gravitational radiation, and solving several problems in gravitational physics, in particular those of direct relevance to cosmic censorship and of the quantum theory of black holes. With the new tools a large number of additional problems in black hole physics and in holographic duality may be solved, such as black hole collisions, black hole phase diagrams, instabilities, holographic dynamics of finite-temperature systems, and potentially any problem that can be formulated in an arbitrary number of dimensions.

The Catalan denominations of meteor showers listed in the interactive map follow the Criteria for the Catalan name of Meteor Showers , approved by the Supervisory Board with the agreement of several specialists in the field of astronomy, among which there are several members of the Institute of Cosmos Sciences.

The course "Astronomia: els secrets de l’univers" , organized by Josep M. Solanes and conducted by teachers of the department, aims to provide people interested in astronomy basic but strict information on the current vision of the Universe.The course lasts 20 hours and prior knowledge is not required.(+ info)

This new course is added to the program "Astronomia i Meteorologia 2015-2016" of the University of Experience, for people older than 55 years, offered by department members since 2014-2015 course.

The "Astronomia i Meteorologia 2015-2016" program is coordinated by Carme Jordi and lasts one academicm year, two hours a week. Its main objective is, firstly, presenting the Universe and observational techniques used to understand it, and the various elements that compose it. On the other hand, providing students a general but rigorous Meteorological knowledge. The course is complemented by observations of the Sun, Moon and planets, and radiosonde station.

The Highly Cited Researchers report from Thomson Reuters is an annual list recognizing leading researchers in the sciences and social sciences from around the world. About three thousand researchers earned this distinction by writing the greatest number of papers ranking among the top 1% most cited for their subject field and year of publication. For the analysis, only Highly Cited Papers in journals indexed in the Web of Science Core Collection during the 11-year period 2003-2013 were surveyed, in order to recognize early and mid-career as well as senior researchers.

Licia Verde has been an ICREA astrophysicist at ICCUB since 2009, where she leads the Cosmology and Large Structure group. Her research topics include theoretical cosmology, cosmic microwave background, large scale structure, galaxy clusters, statistical applications and data analysis. She is also interested in the study of the large-scale structure of the Universe and in the analysis of galaxy surveys.

Thorough her career, Verde has worked in the main cosmological surveys of the last decade: the 2dF Galaxy Redshift Survey (2dFGRS), Wilkinson Microwave Anisotropy Probe (WMAP) and Sloan Digital Sky Survey (SDSS). As a member of the WMAP team, which was awarded with the 2012 Gruber Cosmology Prize, Licia Verde led the effort of the cosmological analysis and interpretation of WMAP data, giving rise to one of the two most cited papers in the history of astronomy (7000 cites) . She also led the measurement and analysis of the higher-order correlations of 2dfGRS and SDSS. In addition she has worked on the joint interpretation of CMB and LSS cosmological surveys including the recently released Planck data. Over the last 5 years her group has been leading the effort of extracting information about fundamental physics from cosmological observations.