Lisa Goh Wan Khee

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Research Interests

I am currently undertaking my PhD thesis titled "Tomographic Coupled Dark Energy with Euclid", under the supervision of Dr Valeria Pettorino. I am interested in studying modified LCDM models, specifically coupled quintessence models, by investigating their potential to alleviate tensions in cosmology.  Coupled quintessence, or coupled dark energy (CDE) cosmologies propose a model whereby dark matter particles feel a fifth force mediated by a scalar field which plays the role of dark energy. The strength of the coupling between the scalar field and the dark matter particles can be encapsulated by the coupling parameter, which in past literature has been generally assumed to take on a constant value. However, we wish to extend this framework by allowing the coupling to evolve with redshift and investigating the effects of such a tomographic CDE model. We use a variety of high and low redshift datasets to derive upper bounds on the value of coupling at different epochs. Ultimately, we aim to derive constraints by employing high-precision weak lensing and galaxy clustering data from Stage IV galaxy surveys like Euclid. To that end, I joined the Euclid Consortium and am contributing as a developer of the Euclid likelihood code CLOE, as well as adapting its pipeline to include the capability of constraining LCDM model extensions.  

On another hand, I am also part of the CFIS/UNIONS collaboration, where I also work with Dr Martin Kilbinger to look at cosmic shear systematics in CFIS/UNIONS, with the ultimate aim of developing a likelihood analysis pipeline to conduct cosmological parameter estimation with UNIONS cosmic shear and 3x2pt data.

In the first two years of my PhD, I was involved in the PHC Pessoa Exchange with the Costar lab at CENTRA, Instituto Superior Técnico, Lisbon. Within the framework of this partnership, we synergised our respective expertise by collaboratively working on a research project of constraining early coupled quintessence models.

I am also one half of the Cosmostat Journal Club organising committee; if you would like to give a seminar at the lab, please feel free to contact Vilasini or me!

Papers

• Goh, L. W. K., Gómez-Valent, A., Pettorino, V. & Kilbinger, M. (2023). Constraining constant and tomographic coupled dark energy with low-redshift and high-redshift probes. Physical Review D, 107(8).
• Goh, L. W. K., Bachs-Esteban J., Gómez-Valent, A., Pettorino, V. & Rubio J. (2023). Observational constraints on early coupled quintessence. arXiv: 2308.06406. (Submitted)

Conferences, Schools and Talks

• Elbereth Conference, March 23-25 2022, Observatoire de Meudon, Paris (Talk)
• Euclid Consortium Meeting 2022, April 26-29 2022, Oslo, Norway
• Advanced Euclid School, June 20-July 1 2022, Les Houches, France
• PESSOA Exchange, Oct 16-22 2022, CENTRA, Instituto Superior Técnico, Lisbon, Portugal (Talk)
• Colloque National Action Dark Energy, Nov 17-18 2022, Marseilles, France (Talk)
• Euclid-France Theory and Likelihood Workshop, Nov 28 2022, IAP Paris (Talk)
• Euclid France Meeting 2022, Nov 30-Dec 2 2022, IAP Paris
• XV Tonale Cosmology Winter School, Dec 4-10 2022, Passo del Tonale, Italy (Poster) 
• Cosmological Physics GDR Kick-off Meeting, Jan 17-19 2023, LPHNE, Paris (Talk)
• Invited Speaker Seminar at IPhT, CEA Paris-Saclay, Feb 23 2023
• Euclid Outreach Talk  to Masters students from the Netherlands, CEA Paris-Saclay, Mar 2023
• TOSCA Kick-off Meeting, Apr 13 2023, Nice, France
• CosmoVerse@Lisbon, May 30-Jun 1 2023, Lisbon, Portugal (Poster)
• Speaker Seminar at CENTRA, Instituto Superior Técnico, Lisbon, Portugal, Jun 7 2023
• Euclid Consortium Meeting 2023, June 18-24 2023, Copenhagen, Denmark (Poster & Flash Talk)
• COSMO'23: 26th International Conference on Particle Physics and Cosmology, Sept 11-15 2023, Madrid, Spain (Talk)
• Euclid IST:Likelihood Meeting, Sept 26-30 2023, ESTEC, Netherlands
• Euclid Theory Science Working Group Meeting, Oct 5-6 2023, Paris, France (Tutorial)
• Lorentz Seminar, Nov 8 2023, Lorentz Institute, Leiden, Netherlands (Seminar)
• Cosmology and Astroparticle Seminar, Nov 10 2023, Université de Genève, Switzerland (Seminar)
• Weak Lensing Journal Club, Nov 27 2023, Waterloo Centre for Astrophysics, Canada (Talk)
• Cosmology and Gravitation Seminar, Nov 30 2023, Perimeter Institute, Canada (Seminar)
• Mila Journal Club, Dec 4 2023, Mila, Montréal, Canada (Talk)

Prior to my PhD, I obtained my Master's degree in Astrophysics at University College London, completing my thesis "Exploring the Cosmological Likelihood of Large Scale Structure as Seen by Euclid" under Prof Benjamin Joachimi, and obtained my bachelor's degree in Physics at the National University of Singapore. 

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