Cosmologist · NCBJ, Warsaw

Mariana Jaber

Theory ⟷ observations · large-scale structure · cosmic web

I work at the interface of theory and observations, using computational methods to study large-scale structure, peculiar velocities, the cosmic web, dark energy, and modified gravity.

Who I am
Portrait of Mariana Jaber

I'm originally from Mexico City, with part of my childhood spent near the Gulf coast in Campeche. I studied physics at the Faculty of Physics of Universidad Veracruzana, then returned to Mexico City for a master's and PhD at UNAM, working with Axel de la Macorra, Octavio Valenzuela, and Miguel Alcubierre on the signatures of dynamical dark energy and modified gravity in baryon acoustic oscillations and galaxy redshift surveys.

In 2019 I moved to Poland for a postdoctoral position in the inhomogeneous cosmology group led by Boudewijn Roukema at NCU Toruń. In 2021 I joined the Computational Cosmology Group at the Center for Theoretical Physics PAS in Warsaw, led by Wojtek Hellwing and Maciej Bilicki, before starting my own group in 2025 as Principal Investigator of the NCN SONATA-funded PAIRS project. I'm currently a PI at the National Centre for Nuclear Research (NCBJ).

I teach and supervise students in cosmology and data analysis, referee for leading journals, and take part in international collaborations including LSST, DESC, and CLUES. Alongside research, I mentor early-career scientists and serve on the leadership board of the Supernova Foundation, which supports women and other underrepresented groups in astronomy.

Outside the lab

I bake, forage for wild mushrooms during Polish mushroom season, and used to practice Taekwon-do and Limalama. I've also helped translate popular-science texts into indigenous languages. I am, by contrast, a famously unsuccessful gardener, despite continued efforts.

What I work on

Theory meets data, on every scale

My research sits at the interface of theoretical models and the computational analysis of astronomical survey data, with a recurring focus on what galaxy motions and environments reveal about gravity and the dark sector.

Pairwise velocities

The typical relative motion of galaxy pairs, modelled down to sub-megaparsec scales and used to extract cosmological information inaccessible to standard clustering or lensing analyses.

Beyond ΛCDM

Parameterizations and numerical tools spanning dynamical dark energy, modified gravity, and alternative dark matter, tested against survey data and simulations.

Galaxy–environment connection

How galaxy size, stellar mass, star-formation rate, and metallicity vary with position in the cosmic web — from voids to filaments and clusters.

Galaxy redshift surveys

Alcock–Paczyński tests on eBOSS/SDSS clustering data, comparing structure along and across the line of sight to constrain the geometry of the Universe.

Full publication list, via the PAIRS project page ↗
Current work

Projects

PAIRS is the first project to get its own page here — more will follow as they take shape.

2025 — ongoing

PAIRS

Pairwise velocities in the context of the cosmic web. Using how galaxies move toward or away from each other to constrain dark matter, dark energy, and gravity on small, highly non-linear scales. Funded by NCN Poland under SONATA-19.

Visit project ↗
Coming next

More projects soon

This space will grow as new projects start. Check back soon!

Thesis & internship opportunities

Work with the group

Open and ongoing projects for bachelor's and master's students, spanning peculiar velocities, the cosmic web, dark energy, and modified gravity.

See open projects ↗
Get in touch

Contact

Address

National Centre for Nuclear Research
Astrophysics Division, Office 506
Ludwika Pasteura 7, 02-093
Warsaw, Poland

Email

mariana.jaber@ncbj.gov.pl
cosmo.marianajbr@gmail.com