Interests (astro-ph.CO/gr-qc)

Gravitational Waves, Gravity, Cosmology, Machine Learning, Dark Energy, Black Holes, Alternative Theories of Gravity, Statistics, Data Analysis, Mathematical Physics, Physics Education

Highlights

Codes:

• PTAfast: PTA correlations from stochastic gravitational wave background
  
• gp6: Gaussian Processes for Physics - designed for late time cosmology with noisy & correlated data
  

Papers:

• R. C. Bernardo and K.-W. Ng, Pulsar and cosmic variances of pulsar timing-array correlation measurements of the stochastic gravitational wave background. JCAP, 2022, (11) 046, arXiv:2209.14834.
  
• R. C. Bernardo and K.-W. Ng, Testing gravity with cosmic variance-limited pulsar timing array correlations. PRD 109, L101502, arXiv:2306.13593.
  
• S. Appleby and R. C. Bernardo, Tadpole Cosmology: Self Tuning Without Degeneracy. JCAP, 2022, (07) 035, arXiv:2202.08672.
  
• R. C. Bernardo, D. Grandon, J. Levi Said, V. H. Cardenas. Parametric and nonparametric methods hint dark energy evolution. Phys. Dark Universe, 36, 101017, arXiv:2111.08289.
  
• R. C. Bernardo. 2021. Gravitational wave signatures from dark sector interactions. PRD, 104, 024070, arXiv:2103.02311.

Full publication list at Inspire HEP, ORCID, and Google Scholar, or my CV.

Signal of a stochastic gravitational wave background in the timing residuals in a pulsar timing array (arXiv:2409.01218)

SGWB-induced inter-pulsar correlations with cosmic variance (arXiv:2209.14834)

Hubble expansion rate reconstructed from observational data via Gaussian Processes (arXiv:2105.12970)

Well tempering: a de Sitter final state independent of the initial conditions and the CC (arXiv:2107.08762)

Research Statement

The current state of cosmology is characterized by a need for new theories and models that can address fundamental questions such as the nature of dark energy and the Hubble tension. I am passionate about exploring alternative theories of gravity that can shed light on these cosmic puzzles. My research focuses on the development of novel models that incorporate irreplaceable features of general relativity, such as gravitational waves, while also making testable astrophysical and cosmological predictions.

In particular, I am fascinated by the largely unexplored nanohertz regime for gravitational wave detection, which has the potential to reveal exotic phenomena such as cosmic strings and phase transitions. Additionally, I am interested in the applications of machine learning in cosmology and have been exploring the use of these techniques to analyze large datasets and extract meaningful insights.

My research objectives include identifying interdisciplinary connections between cosmology and other areas of science, staying up-to-date with the latest research in my areas of interest, and collaborating with others to broaden my scope and produce more impactful research.

Overall, my goal is to contribute to the paradigm shift in cosmology by developing new theories and models that can address the fundamental questions and puzzles of the field.

Experience

• Postdoctoral Fellow, Asia Pacific Center for Theoretical Physics, 2023 -
  
• Postdoctoral Fellow, Institute of Physics, Academia Sinica, 2021 - 2023
  
• Assistant Professor, National Institute of Physics, University of the Philippines, 2021 - 2021
  
• Instructor, National Institute of Physics, University of the Philippines, 2015 - 2020

Education: University of the Philippines

• PhD Physics, Most Outstanding Ph.D., 2017 - 2020
  
• MS Physics, Most Outstanding M.S., 2015 - 2017
  
• BS Physics, Magna Cum Laude, Best Thesis, 2010 - 2015
  

Miscellaneous

Languages: English (fluent), Filipino (mother tongue)
Coding: Command Line, Python, Mathematica, LaTeX

Community Involvement

Referee: PRL, PRD, JCAP, CQG, Phys. Dark Universe, EPJC, Astron. Comput., MPLA, Chinese J. Phys., Sci. Rep., Proceedings of the Physics Society of the Philippines, Philippine Journal of Science

Editor: Proceedings of the Physics Society of the Philippines

Member: CosmoVerse COST Action—Data Analysis and Fundamental Physics Working Groups; SKAO—Pulsars and Cosmology Science Working Groups

Outreach

Host, Liknayan Podcast
Guest, AskTheory (26 Oct. 2023)
Career talk with the PUP Physics Society (29 Sep. 2022) and the UST Applied Physics Society (5 May 2023)
Pinoy Scientists, feature, 20-24 June 2022 (day 1, 2, 3, 4, 5)
Physics Meetup (guest, 20 Oct 2020) and Philippine Astronomical Society (guest, 10 Oct 2020, starting~1:43:50): A Brief History of BHs and Cosmology in the Philippines