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Full-Text Articles in Physics
Dark Energy At Early Times And Act Data: A Larger Hubble Constant Without Late-Time Priors, V. Poulin, Tristan L. Smith, A. Bartlett
Dark Energy At Early Times And Act Data: A Larger Hubble Constant Without Late-Time Priors, V. Poulin, Tristan L. Smith, A. Bartlett
Physics & Astronomy Faculty Works
Recent observations using the Atacama Cosmology Telescope (ACT) have provided ground-based cosmic microwave background (CMB) maps with higher angular resolution than the Planck satellite. These have the potential to put interesting constraints on models resolving the “Hubble tension.” In this paper we fit two models of early dark energy (EDE) (an increase in the expansion rate around matter/radiation equality) to the combination of ACT data with large-scale measurements of the CMB either from the WMAP or the Planck satellite (including lensing), along with measurements of the baryon acoustic oscillations and uncalibrated supernovae luminosity distance. We study a phenomenological axionlike potential …
Early Dark Energy Is Not Excluded By Current Large-Scale Structure Data, Tristan L. Smith, V. Poulin, J. L. Bernal, K. K. Boddy, M. Kamionkowski, R. Murgia
Early Dark Energy Is Not Excluded By Current Large-Scale Structure Data, Tristan L. Smith, V. Poulin, J. L. Bernal, K. K. Boddy, M. Kamionkowski, R. Murgia
Physics & Astronomy Faculty Works
We revisit the impact of early dark energy (EDE) on galaxy clustering using BOSS galaxy power spectra, analyzed using the effective field theory (EFT) of large-scale structure (LSS) and anisotropies of the cosmic microwave background (CMB) from Planck. Recent studies found that these data place stringent constraints on the maximum abundance of EDE allowed in the Universe. We argue here that their conclusions are a consequence of their choice of priors on the EDE parameter space, rather than any disagreement between the data and the model. For example, when considering EFT-LSS, CMB, and high-redshift supernovae data we find the …
Clustering And Halo Abundances In Early Dark Energy Cosmological Models, A. Klypin, V. Poulin, F. Prada, J. Primack, M. Kamionkowski, V. Avila-Reese, A. Rodriguez-Puebla, P. Behroozi, D. Hellinger, Tristan L. Smith
Clustering And Halo Abundances In Early Dark Energy Cosmological Models, A. Klypin, V. Poulin, F. Prada, J. Primack, M. Kamionkowski, V. Avila-Reese, A. Rodriguez-Puebla, P. Behroozi, D. Hellinger, Tristan L. Smith
Physics & Astronomy Faculty Works
Cold Dark Matter with cosmological constant (ΛCDM) cosmological models with early dark energy (EDE) have been proposed to resolve tensions between the Hubble constant H0=100h km ṡ−1Ṁpc−1 measured locally, giving h ≈ 0.73, and H0 deduced from Planck cosmic microwave background (CMB) and other early-Universe measurements plus ΛCDM, giving h ≈ 0.67. EDE models do this by adding a scalar field that temporarily adds dark energy equal to about 10 per cent of the cosmological energy density at the end of the radiation-dominated era at redshift z ∼ 3500. Here, we compare linear and non-linear predictions of a Planck-normalized ΛCDM …
On The Halo-Mass And Radial Scale Dependence Of The Lensing Is Low Effect, J. U. Lange, A. Leauthaud, S. Singh, H. Guo, R. Zhou, Tristan L. Smith, F.-Y. Cyr-Racine
On The Halo-Mass And Radial Scale Dependence Of The Lensing Is Low Effect, J. U. Lange, A. Leauthaud, S. Singh, H. Guo, R. Zhou, Tristan L. Smith, F.-Y. Cyr-Racine
Physics & Astronomy Faculty Works
The canonical Lambda cold dark matter (ΛCDM) cosmological model makes precise predictions for the clustering and lensing properties of galaxies. It has been shown that the lensing amplitude of galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) is lower than expected given their clustering properties. We present new measurements and modelling of galaxies in the BOSS LOWZ sample. We focus on the radial and stellar mass dependence of the lensing amplitude mismatch. We find an amplitude mismatch of around 35 per cent when assuming ΛCDM with Planck Cosmological Microwave Background (CMB) constraints. This offset is independent of halo mass and …
Deepcip: Probing Compensated Isocurvature Perturbations In The Cmb Using Deep Neural Nets, Matiwos A. Mebratu , '21
Deepcip: Probing Compensated Isocurvature Perturbations In The Cmb Using Deep Neural Nets, Matiwos A. Mebratu , '21
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Insights Into Searches For Anisotropies In The Nanohertz Gravitational-Wave Background, Y. Ali-Haïmoud, Tristan L. Smith, C. M. F. Mingarelli
Insights Into Searches For Anisotropies In The Nanohertz Gravitational-Wave Background, Y. Ali-Haïmoud, Tristan L. Smith, C. M. F. Mingarelli
Physics & Astronomy Faculty Works
Within the next several years pulsar timing arrays (PTAs) are positioned to detect the stochastic gravitational-wave background (GWB) likely produced by the collection of inspiralling supermassive black holes binaries, and potentially constrain some exotic physics. So far most of the pulsar timing data analysis has focused on the monopole of the GWB, assuming it is perfectly isotropic. The natural next step is to search for anisotropies in the GWB. In this paper, we use the recently developed PTA Fisher matrix to gain insights into optimal search strategies for GWB anisotropies. For concreteness, we apply our results to the European Pulsar …
The First Three Seconds: A Review Of Possible Expansion Histories Of The Early Universe, R. Allahverdi, M. A. Amin, A. Berlin, N. Bernal, C. T. Byrnes, M. S. Delos, A. L. Erickcek, M. Escudero, D. G. Figueroa, K. Freese, T. Harada, D. Hooper, D. I. Kaiser, T. Karwal, K. Kohri, G. Krnjaic, M. Lewicki, K. D. Lozanov, V. Poulin, K. Sinha, Tristan L. Smith, T. Takahashi, T. Tenkanen, J. Unwin, V. Vaskonen, S. Watson
The First Three Seconds: A Review Of Possible Expansion Histories Of The Early Universe, R. Allahverdi, M. A. Amin, A. Berlin, N. Bernal, C. T. Byrnes, M. S. Delos, A. L. Erickcek, M. Escudero, D. G. Figueroa, K. Freese, T. Harada, D. Hooper, D. I. Kaiser, T. Karwal, K. Kohri, G. Krnjaic, M. Lewicki, K. D. Lozanov, V. Poulin, K. Sinha, Tristan L. Smith, T. Takahashi, T. Tenkanen, J. Unwin, V. Vaskonen, S. Watson
Physics & Astronomy Faculty Works
It is commonly assumed that the energy density of the Universe was dominated by radiation between reheating after inflation and the onset of matter domination 54,000 years later. While the abundance of light elements indicates that the Universe was radiation dominated during Big Bang Nucleosynthesis (BBN), there is scant evidence that the Universe was radiation dominated prior to BBN. It is therefore possible that the cosmological history was more complicated, with deviations from the standard radiation domination during the earliest epochs. Indeed, several interesting proposals regarding various topics such as the generation of dark matter, matter-antimatter asymmetry, gravitational waves, primordial …