Abstract Book
Talks
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Plenary Reviews (live talks)
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Day 1
Wendy Freedman - Tension in H0: Is There a Crisis in Cosmology?
The power spectra of measured temperature and polarization fluctuations in the cosmic microwave background are superbly well-fit by the current standard Lambda Cold Dark Matter (LCDM) model. These fits result in a Hubble constant of about 67 km/s/Mpc. In contrast, measurements of Type Ia supernovae, anchored to the nearby Cepheid distance scale, result in a Hubble constant of about 74 km/s/Mpc. Recent measurements of Type Ia supernovae, anchored instead to the nearby TRGB distance scale, result in a Hubble constant of about 70 km/s/Mpc. I will review several current techniques for measuring H0 and their uncertainties, in the context of the current “Hubble Tension Headache”.
Jo Dunkley - The Hubble constant from the Cosmic Microwave Background
I will describe how we use the Cosmic Microwave Background to infer the Hubble constant, what assumptions we make about the cosmological model in doing so, and how modifications to this model that raise the expansion rate might be distinguished using the CMB. I will review existing measurements from Planck and ground-based CMB observations, and describe prospects for new ground-based data to improve estimates of the Hubble constant and test alternative models.
Day 2
Ulf Danielsson - What if the Hubble tension is for real?
Musings on possible (and impossible) explanations of an unexpected cosmological glitch.
Day 3
Bernard Schutz - Will Gravitational Waves Help Resolve the Tension?
Among the multiplicity of methods to measure H0, the gravitational wave standard siren method stands apart because it doesn’t share with the other methods any systematic sources of error in the measurement of distances. But it will still be some years before we have enough statistics from this method to reduce errors to the 1% level. If the tension is something to do with systematics of the various cosmic distance ladders, then GWs ought to give a hint. If the issue is with cosmological physics, then GWs will probably fall in line with all the other “local” measurement methods. I will review the GW evidence so far, the expectation for reaching 1% with the A+ LIGO upgrade (now funded and under development), the longer-term expectations for high-accuracy measurements of H0 and of the dark-energy equation of state with LISA and 3rd-generation ground-based detectors like ET, and some interesting new ideas that are being discussed in the current literature.
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Invited Speakers (pre-recorded talks)
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Day 1 - Observations
Mickael Rigault - "H0 and Type Ia Supernovae Astrophysical biases"
Nandita Khetan - "SBF to calibrate SNe Ia and evaluate the Hubble Constant"
Martin Millon - "Time-delay Cosmography with Strongly Lensed Quasars"
Tom Collett - "Strong Lensing and The Hubble Constant"
Colin Hill - "Exploring Cosmological Concordance with ACT DR4, Planck, and Beyond"
Dan Scolnic - "New constraints on H0 from SH0ES and SN samples after Gaia EDR3"
Oliver Philcox - "H0 from Galaxy Surveys: With and Without the Sound Horizon"
Leonardo Senatore - "Measuring H0 from Large Scale Structure"
Day 2 - Theory
Eleonora Di Valentino - "The H0 tension and the failure of LambdaCDM model”
Nima Khosravi - "Ginzburg-Landau Theory of Dark Energy"
Eoin O. Colgain - "H0 Tension: implications & a potential way out”
The Swampland program within string theory precludes the cosmological constant, so Lambda-CDM is out. I will review approaches to Hubble tension within string theory and explain the problems with attempts to date. I will make some comments on the early versus late Universe resolution debate and introduce the idea that if Hubble tension is indeed cosmological, some "running in H0" with redshift is inevitable within an FLRW cosmology
Sunny Vagnozzi - "The trouble with Hubble, or: how (not) to solve the Hubble tension"
Despite a huge number of attempts (and false alarms), no compelling model to solve the Hubble tension has been found so far. I will perform a "Hubble autopsy" and discuss why so many proposed models have failed so far. I will close by presenting the "10 commandments" which I believe every "Hubble hunter" should abide by.
Tanvi Karwal - “Hubble tension - headache or opportunity?”
Day 3 - Gravitational Waves, Future, and Grand Panel
Stephen Feeney - Clarifying the Hubble Constant Tension with Multi-Messenger Observations of Compact-Object Mergers
Rachel Gray - "Measuring the Hubble Constant with Dark Standard Sirens"
Rupert Croft - "Direct geometrical measurement of the Hubble constant from galaxy parallax: Predictions for the Vera C. Rubin Observatory and Nancy Grace Roman Space Telescope"
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Contributed talks
Day 1 - Observations
Nikki Arendse - "Cosmic Dissonance: New physics or systematics behind a short sound horizon"
Pablo Lemos - "Why does Planck prefer a low H0?"
Suhail Dhawan - "H0 from Type Ia supernovae: A view from ZTF"
Day 2 - Theory
Anirban Das - "Neutrino Self-interaction as a solution to the Hubble Tension"
Shouvik Roy Choudhury - "Updated Constraints on the Massive Neutrino self-interactions in light of the Hubble tension"
Shao-Jiang Wang - "Chameleon dark energy can resolve the Hubble tension"
Lu Yin - "Releasing the Present Hubble Tension with the ProcaTheory"
Day 3 - Gravitational Waves & Future
Asta Heinesen - "The general luminosity distance ‘Hubble law’ for model-independent cosmological analysis"
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