cv

My curriculum vitae, with personal and professional experience, skills and education track.

General Information

Full Name Santiago Casas
Date of Birth 20th July 1987
Languages Spanish (native), English (C2-proficiency), German (C2), French (B1), Portuguese (A2)
Summary Theoretical Cosmologist with a profound interest in the nature of Dark Matter and Dark Energy. Specializing in the synergies between radio, optical, and gravitational experiments to explore the Universe's large-scale structure. Proficient Python programmer contributing to and developing more than 5 open source projects widely used in the field. Expert in Bayesian statistics, theories of gravity, the primordial Universe, neutrinos, and cosmological parameter estimation. Active member of the Euclid–builder status–and SKAO collaborations. Known for being a flexible and dynamic team player with a keen curiosity across interdisciplinary fields and strong social skills.

Education

  • 2013-2017
    PhD in Theoretical Physics
    Institute of Theoretical Physics, Ruprecht-Karls-Universität Heidelberg, Germany
    • Summa Cum Laude
    • Supervisors
      • Dr. Valeria Pettorino
      • Prof. Luca Amendola
      • Jury Prof. Volker Springel
    • Thesis
      • Non-linear structure formation in models of Dark Energy and Modified Gravity
      • Bayesian statistics, Fisher Information Matrix, Cosmological Parameter Estimation
      • Work for the Euclid Consortium, Theory Science Working Group
      • Galaxy Clustering and Weak Lensing
  • 2011-2013
    Master of Science in Physics
    Institute of Theoretical Physics, Ruprecht-Karls-Universität Heidelberg, Germany
    • Grade 1.2
    • Thesis
      • Fitting and forecasting models of coupled Dark Energy from simulations
    • Supervisors
      • Prof. Luca Amendola
      • Prof. Marco Baldi
  • 2006-2009
    Bachelor of Science in Physics
    University of Costa Rica, San José, Costa Rica
    • Student assistant at the Planetarium and at the Department of Theoretical Physics
  • 1998-2005
    German Abitur
    Deutsche Humboldt Schule, San José, Costa Rica
    • Emphasis: Natural Sciences. Grade: 1.5

Experience

  • 2024-
    Postdoctoral Researcher
    Institute of Cosmology and Gravitation, University of Portsmouth, United Kingdom
    • Euclid research scientist with Builder status
    • Theory Working Group Work Package Likelihood co-lead
    • Theory Working Group pre-launch Key Project coordinator
    • SKAO Synergies and Cosmology, Science Book chapter coordinator
  • 2021-2024
    Postdoctoral Researcher
    Theoretische Teilchenphysik und Kosmologie (TTK), RWTH Aachen University, Germany
    • Theoretical, phenomenological and numerical cosmology
    • Supervised 5 master (1-year each) and 2 bachelor students (3-months each)
    • Topics : Neutrinos in Cosmology, Bayesian Statistics, Likelihoods, Galaxy Clustering and Weak Lensing, Effective Field Theory for Large Scale Structure, Modified Gravity, Gravitational Waves, Machine Learning Emulators
    • Published 7 independent papers, 8 Euclid collaboration papers as lead author and co-signed more than 50 Euclid collaboration papers
    • Development in cosmological software packages: CLOE, MontePython, CosmicFish, CLASS-1loop, JaxCosmo
    • Teaching Assistant
      • Theoretical Mechanics (B.Sc., in German)
      • General Relativity (M.Sc., in English)
      • Advanced Cosmology (M.Sc., in English)
    • Master Student supervision
      • Sabarish V.M., 2021-2022, Validation of MontePython Euclid likelihoods and CosmicFish Fisher matrices
      • Dennis Linde, 2021-2022, 1-loop EFTofLSS implementation into CLASS
      • Sefa Pamuk, 2022-2023, MontePython likelihoods and CosmicFish Fisher Matrices for neutrino parameters
      • Christian Rademacher, 2022-2023, MCMC forecasts and validation against simulations of the CLASS 1-loop code
      • Kostas Revis, 2022-2023, Correlation of Dark Sirens and Euclid Galaxy Clustering
    • Bachelor Student supervision
      • Yun Ling, 2023, Fisher matrices with the Python N-body code CONCEPT for neutrino cosmology
      • Jakob Kramp, 2022, Autodifferentiable Variational Inference for Supernova Cosmology
  • 2018-2021
    Postdoctoral Researcher
    CosmoStat, DAp, CEA, Paris-Saclay, France
    • Theoretical, phenomenological and numerical cosmology for Euclid
    • Supervised 2 Masters 1/2 interns (6-months each)
    • Topics : Bayesian Statistics, Likelihoods, Forecasts, Galaxy Clustering and Weak Lensing, 21cm Radio Cosmology, Modified Gravity, Machine Learning Emulators
    • Published 12 independent papers, 4 Euclid collaboration papers as lead author and co-signed more than 15 Euclid collaboration papers
    • Development in cosmological software packages: CLOE, CosmicFish, JaxCosmo
    • Internship supervisor
      • Senwen Dang, forecasts for alpha-attractor models
      • Raphael Baena, machine learning emulators
    • Course instructor
      • Python, Numpy and Scipy for scientists
      • Einstein Boltzmann solvers in docker
  • 2010-2011
    Physics Lecturer
    Universidad de Costa Rica
    • Lecturer for General Physics II, Laboratory of Physics I and II and Physics for Life Sciences
  • 2009-2010
    Physicist and Software Developer
    Engineering Scientific Services, San José, Costa Rica
    • Developing Finite element methods in Objective-C for engineering applications
  • 2009-2010
    Data Scientist
    DeFi Pulse, Remote, USA
    • Creating graph-databases to analyze decentralized finance portfolios on-chain in Ethereum

Open Source Projects

  • 2024-now
    CLAPP
    • CLAPP: CLASS LLM Agent for Pair Programming
  • 2024-now
    Topo Cobaya
    • A cryptographically time-ordered provable output implementation of the Cobaya framework
  • 2020-now
    jax_cosmo
    • A differentiable cosmology library in JAX
  • 2019-now
    cosmicfishpie
    • Fisher matrix code and Cosmological Theory modelling for Galaxy Clustering, Weak Lensing, Intensity Mapping, CMB and their cross-correlations
  • 2018-now
    looti
    • Emulator for cosmological quantities, using Gaussian Processes, PCA and Dictionary Learning
  • 2014-2020
    cosmomathica
    • Wolfram Mathematica wrapper for cosmological Einstein-Boltzmann-Solvers, non-linear prescriptions and background equations. Together with fishermathica providing a toolkit for general Fisher Matrix forecasting with different cosmological surveys.

Honors and Awards

  • 2024
    • Euclid STAR prize IDEA for the ECI IST:Forecasting team (presented COM effort, Rome 2024, plenary STAR prize talk)
  • 2019
    • Euclid STAR prize for best team, IST:Forecasting Presented prize award talk at the EC Meeting in Helsinki
  • 2011
    • MICIT (Ministry of Science and Technology of Costa Rica) scholarship for Master studies abroad
  • 2010
    • Laboratorio Nacional de Luz Sincrotron (LNLS) Scholarship for a summer internship, Campinas, Brazil.

Academic Interests

  • Dark Energy and Modified Gravity
    • Scalar-tensor theories of gravity such as f(R), Coupled Quintessence, Brans-Dicke
    • Horndeski scalar-tensor theory
    • Screening mechanisms for scalar-tensor theories, such as Chameleons, Vainshtein, etc.
    • Parametrized deviations of General Relativity, with \mu, \Sigma parameters
    • Effective Field Theory of Dark Energy
  • Large Scale Structure
    • Galaxy Clustering, BAO, Redshift Space Distortions
    • Effective Field Theory of LSS. 1-loop perturbation theory using FFTLog
    • Weak Lensing, Cosmic Shear and the 3x2pt correlation function
  • Galaxy Surveys and Cosmological Observations
    • ESA's Euclid space satellite mission, EC consortium member, Builder status
    • SKAO (Square-Kilometer-Array-Observatory), radio-cosmology, Cosmology SWG member
    • Stage-IV Cosmic Microwave Experiments for Temperature and Polarization
    • DESI, Vera Rubin Observatory (LSST survey)
    • Gravitational Waves Dark Sirens in correlation with Galaxy Surveys
  • Bayesian statistics and Machine Learning
    • Fisher information matrix
    • Markov-Chain-Monte-Carlo parameter estimation
    • Cosmological Likelihoods
    • Variational inference
    • Hamilton-Monte-Carlo techniques
    • Differentiable probabilistic programming
    • Gaussian Processes
    • PCA
  • Computational physics and cosmology
    • N-body simulations, runs, and post-processing
    • Einstein-Boltzmann-Solvers (CAMB in Fortran, CLASS in C)
    • Modified Gravity Einstein-Boltzmann Solvers
    • Differentiable likelihoods in JAX
    • ML-based Emulators for cosmological quantities
    • Python code development, High-performance computing, Optimization problems

Community Impact

  • 2015-present
    Referee of High Impact Journals in Cosmology
    • JCAP, Physical Review D, Physics of the Dark Universe, Monthly Notices of the Royal Astronomical Society, Astronomy & Astrophysics
  • 2016-2021
    Winter School Organizer
    • Tonale winter school in Cosmology, for Master and PhD students. 4 times in the local organization team. Arranging of speakers, student support, website, design of program, on-site management.
  • 2019-present
    Alpha-Cen founding member
    • Mentoring for Students of Central America

Invited Talks / Conferences / Workshops / Schools

  • SKAO collaboration meetings; Invited speaker: SKA France (2019), Remote Science Conference (2021), Manchester SWG meeting (2023)
  • International Summer School in Communicating Science; Alexander von Humboldt Foundation, Berlin, 2021
  • MIAPbP Workshop, Garching; Differentiable Methods in Physics, 3 Weeks. By invitation only
  • Notable seminars in past 5 years; COSPAR-Pasadena, Prague, Porto, Leiden, Pascal Institute, Poincaré Institute, Oslo, Portsmouth, Ringberg. First Central American Aerospace Symposium
  • Euclid Collaboration meetings; Lausanne, Lisbon, London, Bonn, Helsinki (plenary prize talk), Oslo, Copenhagen, Rome
  • Invited talks 2023; Brussels Workshop, Saclay Astroparticle Symposium, Institute Seminar at the Bethe Center (Bonn), Cosmology Seminar (CEICO, Prague), Cosmology Seminar (Oslo), TTK Seminar
  • Invited talks 2024; Lorentz Institute (Leiden), Euclid Consortium Rome meeting, Group seminar at University Ghent, 35th Rencontres de Blois 2024

Soft Skills

  • Podcasts: My Cosmic-Sloth Podcast for researchers about the academic world
  • Outreach: Telemedellín Colombia, Delfino Noticias Costa Rica, El Espectador, Colombia. El Colombiano, Colombia. Public talks at libraries and outreach events
  • Blogs: Contributor to Astrobitos, Blog CNRS 80-years anniversary, Euclid Consortium Instagram – social media manager
  • Invited Guest at Podcasts: Astroblog Chile, Starts with a Bang
  • Public talks and outreach events

References

  • Prof. Valeria Pettorino
  • Prof. Martin Kunz
  • Prof. Julien Lesgourgues
  • Prof. Luca Amendola
  • Prof. Marco Baldi
  • Prof. Christof Wetterich
  • Prof. Massimo Pietroni
  • Prof. Alkistis Pourtsidou
  • Prof. Matthias Bartelmann
  • Prof. Kazuya Koyama
  • Dr. Vincenzo Cardone

Other interests

  • Salsa dancing
  • Trumpet playing
  • Hosting Podcasts (Podcastination on all major platforms)
  • Photography
  • YouTuber (9M views)
  • Economics
  • Blockchain
  • Skiing