A new study involving ICCUB researcher Valentí Bosch-Ramon, published last week in Nature Astronomy, has uncovered how collisions between blobs of matter constituting black hole jets can drastically reshape these outflows' magnetic field. 
 

An International team of researchers have uncovered a new piece of the puzzle behind the enigmatic jets of SS 433, one of the best-studied microquasars in our Galaxy. Using advanced three-dimensional magnetohydrodynamics simulations, the team has demonstrated that collisions between individual plasma blobs making up the jets in this system can naturally reorganize the magnetic field, reproducing observational features that have puzzled astronomers for years.

Blackhole jets and SS 433

Black holes are known for swallowing matter, but some of them also produce powerful jets that expel material back into space at enormous speeds. These jets can extend across vast distances and influence their surroundings, yet many aspects of how they work remain poorly understood. Now, astronomers have shed new light on one of the most unusual jet-producing systems in the Milky Way: SS 433. Their results identify a physical mechanism that can explain how the magnetic fields inside SS 433 jets evolve as they travel away from the black hole. 
 

SS 433 is a binary system located about 18,000 light-years from Earth. It consists of a massive star orbiting a compact object that is most likely a stellar-mass black hole. As the black hole pulls material from its companion, part of that material is accelerated into two opposite jets moving at about 26% of the speed of light. The jets of SS 433 also precess, meaning that their direction slowly changes over time, causing them to trace a giant corkscrew-shaped pattern through space.

The hidden collisions shaping magnetic fields

For decades, observations of SS 433 have shown a puzzling behaviour. Near the source, the magnetic field appears to follow the helical, or corkscrew-like, shape of the jets. At larger distances, however, it becomes aligned with the direction in which the jet material is moving, that is, radially away from source center. Astronomers had proposed various explanations for this transition, but no theory had yet demonstrated in a self-consistent way how it could emerge from the jet's internal dynamics. 
 

To investigate the problem, researchers performed three-dimensional numerical simulations that reproduce the behaviour of a relativistic magnetised plasma, a hot gas made of electrically charged particles. The simulations compared two different scenarios. In the first, the jet behaves as a continuous flow. In the second, it is composed of discrete ejecta: individual blobs of plasma launched one after another at slightly different speeds, as observations of SS 433 suggest. 
 

The results reveal that the magnetic field behaves very differently in the two cases. In a continuous jet, the magnetic field largely preserves its original structure and continues to follow the corkscrew-shaped trajectory of the flow. But when the jet consists of discrete ejecta, faster blobs catch up with slower ones launched earlier. These collisions generate internal shock waves, regions where matter is abruptly compressed, much like a traffic jam forms when faster cars encounter slower traffic ahead. 
 

According to the simulations, these collisions compress, stretch and reorganise the magnetic field lines. As a result, the field gradually loses its alignment with the corkscrew path of the jet and instead becomes aligned with the radial direction in which the plasma blobs are moving. This reproduces remarkably well the magnetic-field orientations measured in radio observations of SS 433. 
 

The study also found that the collisions do not destroy the jets. On the contrary, they merge smaller ejecta into larger, elongated structures that are more stable and can travel greater distances without breaking apart. This suggests that interactions between ejecta may play an important role not only in shaping magnetic fields but also in determining how jets evolve over time on large scales. 
 

Valentí Bosch-Ramon, researcher at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) and co-author of the study, highlights: "these simulations demonstrate how microquasar jets interacting with their environments can reshape the plasma properties in unexpected ways; they are thus a powerful tool that in combination with observations can probe the jet structure in ways not directly accessible by these observations alone." 
 

Although the simulations were specifically designed to reproduce the properties of SS 433, the researchers believe that the same mechanism could operate in other systems that produce precessing jets. The work therefore provides a new framework for interpreting observations of black holes and other compact objects, while offering fresh clues about the role of magnetic fields in some of the Universe's most extreme environments.

Reference:

José López-Miralles, Manel Perucho, David Vallés-Pérez, José-María Martí, Valentí Bosch-Ramon, James C. A. Miller-Jones, Sara E. Motta, Simone Migliari & Herman L. Marshall. Magnetic field topology and colliding discrete ejecta in the precessing jets of SS 433. Nature Astronomy (2026). DOI: 10.1038/s41550-026-02922-6.

Toni Rubio-Abadal, researcher at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB), has been awarded a prestigious Leonardo Grant from the BBVA Foundation. The fellowship will support his project Quantum Motion Control in Atomic Arrays (QUMATO), aimed at developing new techniques to manipulate the quantum motion of neutral atoms with unprecedented precision.

Quantum science aims to understand and control physical phenomena at the microscopic scale, where quantum effects dominate. A central goal of the field is to precisely manipulate individual quantum degrees of freedom, a capability that is essential for emerging technological applications such as quantum computing and quantum metrology. One of the leading platforms for quantum science and technology are neutral atoms trapped in optical tweezers. By cooling the atoms with lasers, loading them into optical traps and detecting them at the individual level, researchers can build complex quantum systems with critical applications like atom-based quantum computing. However, in these platforms, atomic motion often takes a secondary role, seen mostly as a limitation.

The QUMATO project will explore new laser-based tools to prepare quantum states of motion with extremely high fidelity. These techniques will be implemented in a new experimental platform based on arrays of ultracold cesium atoms, currently under construction at the Atomic Quantum Science Lab (https://aqslab.fqa.ub.edu/home) at the University of Barcelona. The platform is designed to enable precise, site-resolved control of both internal and motional degrees of freedom at the single-atom level.

“Many experiments based on laser-cooled atoms are pushing the forefront of quantum science and technology.” says Toni Rubio-Abadal. “In Spain there are few experimental groups in this field, most of them in research institutes. The QUMATO project will help me develop the first cold-atom experiment inside a university setting.”

Enhanced control of quantum motion is expected to unlock multiple applications. In neutral-atom quantum computing, reducing motional excitations can improve gate fidelities and coherence times. In quantum metrology, it can increase the precision of atomic clocks by minimizing systematic uncertainties. However, these are not the main directions Dr. Rubio-Abadal wants to pursue: “What I am most excited about is the possibility of assembling low-entropy quantum gases in a bottom-up manner, constructing many-body systems atom by atom with tailored properties. This is a thrilling challenge that I really look forward to, and this Leonardo fellowship will be a major first step in this research direction.”

The Leonardo Grants for Researchers and Cultural Creators, awarded by the BBVA Foundation, support innovative and exploratory projects across a broad range of disciplines. Aimed at researchers at an intermediate stage of their careers, these highly competitive grants provide flexible funding to develop ambitious, high-impact ideas. This award reinforces ICCUB’s position as a leading centre in quantum science and highlights its commitment to advancing cutting-edge experimental platforms for next-generation quantum technologies.

The awards, promoted by the Government and the Catalan Foundation for Research and Innovation (FCRI), have celebrated their 36th edition this year. The ceremony took place at the Teatre Nacional de Catalunya, presided over by the President of the Government of Catalonia, Salvador Illa, and the Catalan Minister for Research and Universities, Núria Montserrat. In addition to Blagorodnova, other awardees were Luis Serrano, who received the National Research Award; the Eurecat Foundation, which received the National Award for the Transfer of Knowledge and Innovation; the ARI Project (Assistance and Research in Immunotherapy), honoured with the National Award for Patronage and Public-Private Scientific Collaboration; the University of Lleida and the University of Sherbrooke (Canada), recipients of the National Award for Innovation in the Creation of a Science-Based Company, and science communicator Pere Estupinyà, awarded the “Joan Guinovart i Cirera” National Award for Scientific Communication.

Nadejda Blagorodnova Mujortova’s research focuses on time-domain observational astronomy, which studies transient astrophysical phenomena such as supernovae, stellar mergers or stars torn apart by supermassive black holes. With the Common Envelope Transients – Progenitors, Precursors, and Properties of their Outbursts (CET-3PO) research group, funded by a grant from the European Research Council (ERC), she studies the interaction and merger of close binary stars. These studies combine stellar evolution models with observations from the most advanced ground-based telescopes, such as the Gran Telescopio de Canarias, the Very Large Telescope (Chile) and the Southern African Large Telescope (South Africa), and observations from space telescopes such as Hubble and the James Webb Space Telescope.

ICCUB researchers Carla Marin Benito and Paloma Laguarta attended last week the International Conference on Computing in High Energy and Nuclear Physics (CHEP), the world’s leading conference on computing for particle, nuclear, and astroparticle physics, held this year in Thailand. The event brought together more than 500 international participants and had significant national impact, including coverage in local media and the presence of Her Royal Highness Princess Maha Chakri Sirindhorn at the opening ceremony.

Marin Benito was chair of the scientific track “Offline Data Processing,” one of the main areas of the event, focused on the systems and methodologies used to process and analyse data from large-scale scientific infrastructures. In addition, she was responsible for presenting the summary of this track during the final session of the conference, highlighting key developments and challenges discussed throughout the week.

She also attended CHEP as a representative of the LHCb experiment at CERN, where she currently serves as Vice-Coordinator for Software and Computing, a central role in the development and coordination of the tools required to process the vast amounts of data generated by the detector.

The conference also featured the participation of ICCUB PhD researcher Paloma Laguarta, who presented a project on the use of autoencoders for real-time event selection. Her work explores machine learning techniques to improve trigger systems in particle physics experiments, enabling more efficient identification of relevant events for further analysis. The contribution was very well received by the scientific community.

CHEP is the leading international forum for experts in scientific computing applied to fundamental physics, covering topics such as large-scale data processing, distributed infrastructures, artificial intelligence, and software development for major international collaborations. ICCUB’s participation in this conference highlights the institute’s active role in a strategic field that is essential for the future of physics research.

More information about the conference: https://indico.cern.ch/event/1471803/overview

Alejandro Romero Ros, a former postdoctoral researcher at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) and currently an external collaborator of the institute, has been awarded an Honorary Mention from the Institute of Catalan Studies (IEC) Section of Science and Technology in the field of Physical Sciences, in honor of Montserrat Casas.

The distinction recognizes his doctoral thesis, entitled On the Controlled Generation of Nonlinear Structures in Bose–Einstein Condensates, which he defended at the University of Hamburg in 2024. His work focuses on the study and control of nonlinear structures in Bose–Einstein condensates, a key topic in quantum physics and ultracold matter with both fundamental and applied implications.

The Sant Jordi Awards 2026 of the Institute of Catalan Studies (IEC) annually recognize excellence across a wide range of academic disciplines and are among the most prestigious distinctions in the Catalan academic landscape.

At ICCUB, we warmly congratulate Alejandro Romero Ros on this achievement, which highlights the quality of his research and his scientific trajectory.
The full list of awardees is available here.

Last night, the 5,000 fiber-optic eyes of the Dark Energy Spectroscopic Instrument (DESI) swiveled onto a patch of sky near the Little Dipper. Roughly every 20 minutes, they locked on to distant pinpricks of light, gathering photons that had traveled toward Earth for billions of years. When the sun rose, collaborators marked completion of a major milestone: successfully surveying all of the area in DESI’s originally planned map of the universe.

The five-year survey, finished ahead of schedule and with vastly more data than expected, has produced the largest high-resolution 3D map of the universe ever made. Researchers use that map to explore dark energy, the fundamental ingredient that makes up about 70% of our universe and is driving its accelerating expansion.

By comparing how galaxies clustered in the past with their distribution today, researchers have traced dark energy’s influence over 11 billion years of cosmic history. Surprising results using DESI’s first three years of data hinted that dark energy, once thought to be a “cosmological constant,” might be evolving over time. With the full set of five years of data, researchers will have significantly more information to test whether that hint disappears or grows. If confirmed, it would mark a major shift in how we think about our universe and its potential fate, which hinges on the balance between matter and dark energy.

“We are very eager to obtain the analysis of these five years of data and what they tell us about the nature of dark energy,” says Adriana Nadal-Matosas, a PhD student at the ICCUB who studies the non-Gaussian signal of DESI galaxies. “In a few months we will be able to learn a bit more about whether DESI data are statistically consistent with measurements of the cosmic microwave background within the cosmological constant framework,” Nadal-Matosas adds, referring to the potential discrepancy between these two experiments.

DESI’s quest to understand dark energy is a global endeavor. The international experiment brings together the expertise of more than 900 researchers (including 300 PhD students) from over 70 institutions. The project is managed by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), and the instrument was constructed and is operated with funding from the DOE Office of Science. DESI is mounted on the U.S. National Science Foundation’s Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory (a program of NSF NOIRLab) in Arizona.

“DESI’s five-year survey has been spectacularly successful,” said Michael Levi, DESI director and a scientist at Berkeley Lab. “The instrument performed better than anticipated. The results have been incredibly exciting. And the size and scope of the map and how quickly we’ve been able to execute is phenomenal. We’re going to celebrate completion of the original survey and then get started on the work of churning through the data, because we’re all curious about what new surprises are waiting for us.”

DESI has now measured cosmological data for six times as many galaxies and quasars as all previous measurements combined. The collaboration will immediately begin processing the completed dataset, with the first dark energy results from DESI’s full five-year survey expected in 2027. In the meantime, DESI scientists continue to analyze the survey’s first three years of data, refining dark energy measurements and producing additional results on the structure and evolution of the universe, with several papers planned later this year.

“The Dark Energy Spectroscopic Instrument has truly exceeded all expectations, delivering an unprecedented 3D map of the universe that will revolutionize our understanding of dark energy,” said Kathy Turner, Program Manager for the Cosmic Frontier in the Office of High Energy Physics at the Department of Energy. “From its inception, we envisioned a project that would push the boundaries of cosmology, and to see it come to such a spectacularly successful completion for its initial survey, ahead of schedule and with such rich data, is incredibly rewarding. The dedication and ingenuity of the entire DESI collaboration have made this world-leading science a reality, and I am immensely proud of the groundbreaking results we are already seeing and the discoveries yet to come as we continue to explore the mysteries of our cosmos.”

An observing machine

DESI began collecting data in May 2021. Since then, the instrument has far surpassed the collaboration’s original goals. The plan was to capture light from 34 million galaxies and quasars (extremely distant yet bright objects with black holes at their cores) over the five-year sky survey. DESI instead observed more than 47 million galaxies and quasars and 20 million stars.

The project’s success is even more impressive in light of several challenges. DESI is a complicated machine with thousands of parts to maintain. In 2020, final tests of the instrument were interrupted by the COVID-19 pandemic. In 2022, the Contreras Fire swept over Kitt Peak but, through the efforts of firefighters and staff, did not damage the telescope. Recovery efforts were slowed by monsoons and mudslides.

“DESI is a complicated but wonderfully robust system, and it’s been a huge amount of fun to see it come together and work so well for such a long time,” said Connie Rockosi, co-instrument scientist for DESI and a professor at UC Santa Cruz and UC Observatories. “We’ve learned about the instrument over five years, and we know its personality and behavior pretty well. That’s important because having the instrument be so efficient is why we’re here at the end of DESI’s original survey with such great data and so much science coming out.”

To map objects, researchers use specially-designed software to optimize DESI observations and decide where to point the telescope. Robotic positioners precisely line up optical fibers that are accurate to within 10 microns, or less than the width of a hair. Ten spectrographs then measure and split the light into its separate colors to determine each object’s position, velocity, and chemical composition. Each night, roughly 80 gigabytes of data streams through ESnet, DOE’s high-speed science network, to supercomputers at Berkeley Lab’s National Energy Research Scientific Computing Center (NERSC). Initial processing lets researchers do quality assurance and make any adjustments needed for the next night of observations.

Collaborators across the project found ways to make DESI more efficient. Efforts spanned telescope operations, tweaks to the instrument hardware, updates to software, observing protocols, methods to reduce the data, and more.

“There’s been constant monitoring and intervention to make the whole thing tick,” said Adam Myers, co-manager for DESI’s survey operations and professor at the University of Wyoming. “And the DESI team is remarkable. This huge group of people have all been working on whether they could save one or two or three percent in their particular area, and when you add it all up, it results in these amazing gains in efficiency.”

DESI is designed to make several overlapping passes of the sky to observe its full footprint (and sometimes make repeated observations of faint objects). The survey was so efficient, the team completed an entire additional pass over the sky for the “Bright-Time Survey,” which is carried out when reflected light from the moon hinders observations of faint and distant objects. All told, DESI made five passes during the Bright-Time Survey and seven during the Dark-Time Survey, covering about two-thirds of the northern night sky.
 

The sky’s the limit

DESI will continue observations through 2028 and grow its map by about 20%, from 14,000 square degrees to 17,000 square degrees. (For comparison, the moon covers approximately 0.2 square degrees, and the full sky has over 41,000 square degrees). The extended map will cover parts of the sky that are more challenging to observe: areas that are closer to the plane of the Milky Way, where bright nearby stars can make it harder to see more distant objects, or further to the south, where the telescope must account for peering through more of Earth’s atmosphere.

The experiment will also revisit the existing area of the map to collect data from a new set of galaxies: more distant and faint “luminous red galaxies.” These will provide an even denser and more detailed map in the regions DESI has already covered, giving researchers a clearer picture of the universe’s history.

Researchers will also study nearby dwarf galaxies and stellar streams, bands of stars torn from smaller galaxies by the Milky Way’s gravity. The hope is to better understand dark matter, the invisible form of matter that accounts for most of the mass in the universe but has never been directly detected.

The extended map is already underway. When it became clear that DESI would operate beyond its original survey plan, researchers began interleaving the new observations with the ongoing DESI survey to optimize the use of telescope time and keep the instrument from sitting idle.

“We’ve built a remarkable piece of equipment that met all our expectations and then some,” Levi said. “Now we’re pushing beyond our original plan. We don’t know what we’ll find, but we think it’ll be pretty exciting.”

DESI is supported by the DOE Office of Science and by the National Energy Research Scientific Computing Center, a DOE Office of Science national user facility. Additional support for DESI is provided by the U.S. National Science Foundation; the Science and Technology Facilities Council of the United Kingdom; the Gordon and Betty Moore Foundation; the Heising-Simons Foundation; the French Alternative Energies and Atomic Energy Commission (CEA); the Secretariat of Science, Humanities, Technology and Innovation (SECIHTI) of Mexico; the Ministry of Science and Innovation of Spain; and by the DESI member institutions.

The DESI collaboration is honored to be permitted to conduct scientific research on I’oligam Du’ag (Kitt Peak), a mountain with particular significance to the Tohono O’odham Nation.

An international team of researchers has proposed a new way to address the “Hubble tension” by comparing estimates of the Universe’s age rather than its expansion rate. Using precise stellar data, they determined ages for carefully selected very old Milky Way stars and found a most likely age of about 13.6 billion years. Under the assumption of the standard cosmological model, this age is inconsistent with the younger Universe implied by Cepheid- and Supernova-based expansion measurements, but it is compatible with the older age inferred from observations of the cosmic microwave background—thereby adding a new perspective to the ongoing Hubble tension debate.

One of the most debated questions in modern cosmology is the value of the Hubble constant, which measures how fast the Universe is expanding today. For years, the different traditional methods have provided inconsistent results, and despite many efforts, there is still no clear explanation. Since the Gaia space mission, our Milky Way has increasingly become a “close-up laboratory” for cosmology.

The study, led by the Università di Bologna and the Leibniz Institute for Astrophysics Potsdam (AIP), opens up an alternative approach to the methods used so far. Instead of searching for the discrepancies directly in the expansion rate, it was translated into a so-called age tension. Cosmological models link the current rate of expansion of the Universe directly to its age: a higher value of the Hubble constant implies a younger Universe, while a smaller value corresponds to an older one. The Hubble constant measurements currently in tension, based on measurements in the local Universe from Cepheids and Supernovae on the one hand and on the early Universe from the cosmic microwave background on the other, correspond to cosmic ages of about 13 and 14 billion years, respectively. But which of these two ages is the correct one?

The Universe cannot be younger than the oldest stars it contains. If the ages of the oldest stars in our Galaxy can therefore be measured with high precision, a robust lower limit on the age of the Universe can be established.

The project was initiated by an unusual collaboration between two research fields that have traditionally been separate: a cosmology group at the University of Bologna and a stellar archaeology group at the AIP.
 

ICCUB-IEEC Contribution

Researchers from the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) and the Institute of Space Studies of Catalonia (IEEC) also played a significant role in enabling these results. 

Friedrich Anders (ICCUB–IEEC) is one of the main developers of StarHorse, the computational framework used to determine precise stellar ages in this study. He contributed to the analysis, in particular to the evaluation of systematic uncertainties. “Isochrone fitting, the method we use to estimate ages, requires comparing a star’s observed brightness, colour, temperature, and composition with large grids of stellar evolution models,” says Dr. Anders. “Although the idea is simple, the underlying observables are highly interconnected”.

He also emphasises the importance of Gaia’s unprecedented precision: “Gaia’s parallax uncertainties below one percent were crucial for tightly constraining stellar masses and thus their ages. Decades of work by the Gaia data processing teams at ICCUB, IEEC, and across Europe made it possible to identify around one hundred of the very oldest stars with high-quality age estimates. Further improvements are expected with Gaia DR4, scheduled for release in December 2026.” 

Licia Verde (ICREA–ICCUB) and Raul Jiménez (ICREA–ICCUB), along with the ICCUB Cosmology group, have been instrumental in shaping the theoretical framework for this study, and are internationally recognised for pioneering the use of stellar ages as cosmological probes. "Stellar ages are of paramount importance to unveil the physics of the standard model of cosmology LCDM, among them the Hubble tension", says Raul Jiménez. "The ICCUB has been leading its use as cosmic chronometers for such purpose. These new age determinations will help to achieve this goal."

The work was based on an existing catalogue of stellar ages from a previous study from AIP, in which precise ages were measured by combining multiple pieces of information on the brightness, position, and distance of more than 200’000 stars in the Milky Way. A crucial element was the use of the third data release of the ESA Gaia mission, which provides exceptionally accurate parallaxes and spectra and thus improved stellar parameters for a large number of nearby stars.

From this extensive dataset, a carefully selected sample of the oldest stars with the most reliable age estimates was compiled. The focus was on quality over quantity, choosing only stars whose ages could be determined robustly by the StarHorse code and removing potential contaminants. The result: for the final sample of around one hundred stars, the most probable age is about 13.6 billion years. This is too old to be compatible with the age of the Universe inferred from Cepheids and Supernovae (unless other ingredients in the cosmological models are varied), but it aligns well with the cosmic age inferred from the cosmic microwave background.

“This project beautifully shows how combining expertise from different fields can open new windows on fundamental questions. Measuring the age of stars is, in itself, a complex challenge, but we now live in an era in which the quantity and quality of available data allow us to achieve unprecedented precision and, for the first time, statistically significant results. With the next Gaia data release on the horizon, stellar ages could become a fundamental anchor for cosmology.” says Elena Tomasetti from the Università di Bologna and first author of the study.

“With Gaia, the Milky Way has effectively become a near-field cosmology laboratory. We can now estimate stellar ages with unprecedented precision. The next breakthrough will be accuracy, anchoring the Galactic timeline with far greater certainty. The HAYDN mission concept, with AIP participation, aims to provide that decisive step.“ adds Cristina Chiappini from AIP.

Although these results are not yet conclusive due to remaining uncertainties in stellar age estimates, they provide an important independent constraint in the debate over the Hubble tension. At the same time, they highlight the potential of near-field cosmology and, in particular, the research at the AIP to tackle fundamental cosmological questions using the oldest “fossils” of the Milky Way. With the fourth Gaia data release, further significant progress is expected—and with it, even stronger constraints on the age of the Universe and the value of the Hubble constant.
 

Further information

E. Tomasetti et al. 2026: The oldest Milky Way stars: New constraints on the age of the Universe and the Hubble constant, A&A, 707, A111, https://doi.org/10.1051/0004-6361/202557038 (ArXiv)

S. Nepal et al. 2024: Discovery of the local counterpart of disc galaxies at z > 4: The oldest thin disc of the Milky Way using Gaia-RVS, A&A, 688, A167 https://doi.org/10.1051/0004-6361/202449445 (ArXiv)

The Institute of Cosmos Sciences of the University of Barcelona (ICCUB) will host three new PhD researchers through the prestigious INPhINIT doctoral fellowships awarded by the ”la Caixa” Foundation. These highly competitive fellowships aim to attract and retain outstanding international talent at leading research centres in Spain and Portugal.

As part of the 2025 call, the ”la Caixa” Foundation has awarded 60 doctoral and 40 postdoctoral fellowships to excellent researchers to carry out their projects. The programme not only provides competitive funding, but also offers comprehensive cross-disciplinary training in areas such as scientific communication, leadership, and career development .
 

The three doctoral researchers joining ICCUB will contribute to the institute’s research in fundamental physics, strengthening its activities in cosmology, gravitation, and theoretical physics.

International talent in fundamental physics
 

Mariami Mtchedlidze, from Georgia, will pursue a PhD in Particle Physics and Gravitation. Her academic path has been shaped by strong international experience, with studies in Tbilisi, Rome, and Bremen במסגרת the Erasmus Mundus Master’s programme in Astrophysics and Space Science. Her research interests focus on gravitational physics and cosmology, with the aim of fostering collaboration and innovation in these fields.

Nell Weidemann, born in Liège (Belgium), joins the PhD programme in Physics. Specialised in cosmology and the large-scale structure of the Universe, she completed both her Bachelor’s and Master’s degrees at the University of Liège with high honours. She aims to combine research and teaching, contributing to major open questions in physics while inspiring future generations.

Sebastián Nicolás Mendoza Vasconez, from Quito (Ecuador), will carry out his PhD in Physics with a focus on theoretical physics. He completed his undergraduate studies at Jacobs University Bremen and further specialised through the Mathematical Tripos (Part III) at the University of Cambridge. His interests lie at the intersection of quantum physics and gravity, particularly in holography, as well as in condensed matter physics, machine learning, and quantum information science.

A programme fostering research excellence
 

The ”la Caixa” Foundation fellowship programme is one of the most significant initiatives promoted by a private organisation in Europe, both in terms of the number of fellowships awarded and the breadth of disciplines covered. In this edition, more than €22 million will be allocated to doctoral and postdoctoral fellowships, co-funded by the European Commission through the Marie Skłodowska-Curie COFUND Actions .

With the incorporation of these three researchers, ICCUB continues to strengthen its international outlook and its commitment to excellence in cosmos sciences.
 

Óscar Jiménez Arranz, former ICCUB-IEEC doctoral student, has been honored with the Premi Extraordinari de Doctorat 2023–2024 in recognition of the outstanding quality of his PhD thesis. This award is granted annually by the University of Barcelona to graduates whose research demonstrates exceptional academic excellence and make significant contributions to their field.

Dr. Jiménez Arranz completed his PhD at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) under the supervision of Mercè Romero and former ICCUB Director Xavier Luri. His thesis, “Dynamical characterisation of the Magellanic Clouds with Gaia data and the KRATOS simulations”, focuses on the detailed dynamics of our closest neighbouring galaxies, the Large and Small Magellanic Clouds (LMC and SMC), by combining the unprecedented astrometric dataset from the Gaia mission with advanced numerical simulations.

The award ceremony will take place on 28 April in the Paranimf of the Historic Building at the University of Barcelona, celebrating the achievements of doctoral graduates from the 2023–2024 academic year. Faculty members, fellow researchers, and family will join the event to recognize the remarkable accomplishments of the awardees.

The Extraordinary PhD Prize highlights both academic merit and research excellence. Following his PhD, Óscar Jiménez Arranz has continued his research career as a postdoctoral researcher at Lund University, further advancing the study of galactic dynamics.

We warmly congratulate Óscar Jiménez Arranz on this outstanding achievement and look forward to his continued contributions to astrophysics.

The Ministry of Science, Innovation and Universities has awarded Xavier Roca-Maza, researcher at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB), a Consolidación Investigadora 2026 grant for the project NGEDF (Next-Generation Energy Density Functionals).

The Consolidación Investigadora programme aims to strengthen and consolidate the scientific careers of established researchers by supporting ambitious, high-impact research projects. In the 2025 call, the NGEDF project has been selected for its innovative approach to one of the central challenges in nuclear theory: the development of accurate and predictive nuclear energy density functionals.

Towards next-generation nuclear models

The NGEDF project aims to improve how scientists model and understand the atomic nucleus. These models are essential for explaining why nuclei have certain sizes, masses and properties, but current approaches rely on mathematical formulas that were largely designed by hand and can be too rigid to fully capture the complexity of nuclear matter.

Instead of fine-tuning existing formulas, NGEDF takes a different approach. The project will use advanced computer algorithms, including machine learning, to automatically explore and build new mathematical descriptions of nuclei. By combining large sets of nuclear data with physical principles, this method will identify the simplest and most accurate models that can reliably predict nuclear properties, while also indicating how uncertain those predictions are.

This new strategy is expected to lead to more reliable and transparent nuclear models, opening the door to a deeper understanding of atomic nuclei and improving predictions in areas where experimental data are scarce or difficult to obtain.

Impact on nuclear physics and beyond

By advancing the foundations of nuclear density functional theory, the NGEDF project is expected to have a significant impact on multiple areas of nuclear physics, from the structure of exotic nuclei to applications in nuclear astrophysics, including the physics of neutron stars. More broadly, the project exemplifies how modern data science techniques can be integrated into fundamental theoretical physics while preserving physical insight and interpretability. 

This grant further reinforces ICCUB’s role as a leading center in theoretical nuclear physics and strengthens its contribution to frontier research at the intersection of physics, mathematics and artificial intelligence.