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My name is George Alestas and I have a PhD in Cosmology.
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George Alestas

id: g.alestas · role: postdoc

01 — About

A few words about me

I am a Postdoctoral researcher at the Cosmology group of Instituto de Física Teórica (IFT) in Madrid. I am a member of the Euclid, COMPACT, LIGO, Virgo and LISA collaborations. Before that, I received my PhD from the University of Ioannina with Prof. Leandros Perivolaropoulos as my advisor.

My PhD was all about the Hubble tension: the expansion rate of the Universe comes out different depending on how you measure it. All the methods should agree, give or take, but much to our surprise they DON’T!! Is something wrong with the methodologies, or is it a hint of new and exciting physics? To paraphrase Sidney Coleman, God only knows at the moment, and someday I hope you and me as well.

These days I mostly work on what new data can tell us about the dark sector and the early Universe. I use DESI data and Euclid forecasts to test models of dark energy, such as quintessence, and of inflation, such as α-attractors. I also search for planetary-mass black holes in gravitational-wave data, and apply machine learning to cosmological model selection and tests of gravity. When I’m not doing physics I enjoy watching movies, some tv series, reading books, programming and cooking for the lucky few that can handle it...

Affiliation
IFT (UAM-CSIC), Madrid
Collaborations
Euclid · COMPACT · LIGO · Virgo · LISA
Address
C/ Nicolás Cabrera 13-15, Campus de Cantoblanco UAM, 28049 Madrid

02 — Work

Research

I work at the interface of cosmological data and theory: what current and upcoming surveys can tell us about dark energy, inflation, gravity and the early Universe.

  • dark-energy
  • quintessence
  • DESI
  • Euclid
  • inflation
  • gravitational-waves
  • primordial-black-holes
  • machine-learning
  • hubble-tension
  • modified-gravity
  • cosmic-topology

>> Selected publications

2025Dark energy

Has DESI detected exponential quintessence?

Y. Akrami, G. Alestas, S. Nesseris

arXiv preprint

2024Dark energy

To curve, or not to curve: Is curvature-assisted quintessence observationally viable?

G. Alestas, M. Delgado, I. Ruiz, Y. Akrami, M. Montero, S. Nesseris

Phys. Rev. D 110, 106010

2021Hubble tension

A w–M phantom transition at zt < 0.1 as a resolution of the Hubble tension

G. Alestas, L. Kazantzidis, L. Perivolaropoulos

Phys. Rev. D 103, 083517

2020Hubble tension

H0 tension, phantom dark energy, and cosmological parameter degeneracies

G. Alestas, L. Kazantzidis, L. Perivolaropoulos

Phys. Rev. D 101, 123516

>> Latest papers

inspirehep.net — live feed

$ fetch --source inspire --author alestas --latest 5

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