Jonathan R. Pritchard

Constraining reionization using 21 cm observations in combination with CMB and Lyman-alpha forest data (2009)

Pritchard, Jonathan R., Loeb, Abraham, Wyithe, J. Stuart B.

In this paper, we explore the constraints on the reionization history that are provided by current observations of the Lyman-alpha forest and the CMB. Rather than using a particular semi-analytic...

Forecasted 21 cm constraints on compensated isocurvature perturbations (2009)

Gordon, Christopher, Pritchard, Jonathan R.

A "compensated" isocurvature perturbation consists of an overdensity (or underdensity) in the cold dark matter which is completely cancelled out by a corresponding underdensity (or overdensity) in...

On the Detectability of the Hydrogen 3-cm Fine Structure Line from the EoR (2008)

Dijkstra, Mark, Lidz, Adam, Pritchard, Jonathan R., Greenhill, Lincoln J., Mitchell, D. A., Ord, S. M., ...

A soft ultraviolet radiation field, 10.2 eV < E 2p_3/2) against the Cosmic Microwave Background out to very high redshifts. In particular, the optical depth in the fine-structure line through...

Constraining massive neutrinos using cosmological 21 cm observations (2008)

Pritchard, Jonathan R., Pierpaoli, Elena

Observations of neutrino oscillations show that neutrinos have mass. However, the best constraints on this mass currently come from cosmology, via measurements of the cosmic microwave background and...

Evolution of the 21 cm signal throughout cosmic history (2008)

Pritchard, Jonathan R., Loeb, Abraham

The potential use of the redshifted 21 cm line from neutral hydrogen for probing the epoch of reionization is motivating the construction of several low-frequency interferometers. There is also much...

21-cm fluctuations from inhomogeneous X-ray heating before reionization (2007)

Pritchard, Jonathan R., Furlanetto, Steven R.

Many models of early structure formation predict a period of heating immediately preceding reionization, when X-rays raise the gas temperature above that of the cosmic microwave background. These...

Galaxy surveys, inhomogeneous re-ionization and dark energy (2007)

Pritchard, Jonathan R., Furlanetto, Steven R., Kamionkowski, Marc

We examine the effect of inhomogeneous re-ionization on the galaxy power spectrum and the consequences for probing dark energy. To model feedback during re-ionization, we apply an ansatz setting the...

21 cm fluctuations from inhomogeneous X-ray heating before reionization (2006)

Pritchard, Jonathan R., Furlanetto, Steven R.

Many models of early structure formation predict a period of heating immediately preceding reionization, when X-rays raise the gas temperature above that of the cosmic microwave background. These...

The Scattering of Lyman-series Photons in the Intergalactic Medium (2006)

Furlanetto, Steven, Pritchard, Jonathan R.

We re-examine scattering of photons near the Lyman-alpha resonance in the intergalactic medium (IGM). We first derive a general integral solution for the radiation field around resonance when spin...

Galaxy surveys, inhomogeneous reionization, and dark energy (2006)

Pritchard, Jonathan R., Furlanetto, Steven R., Kamionkowski, Marc

We examine the effect of inhomogeneous reionization on the galaxy power spectrum and the consequences for probing dark energy. To model feedback during reionization, we apply an ansatz setting the...

Descending from on high: Lyman series cascades and spin-kinetic temperature coupling in the 21 cm line (2005)

Pritchard, Jonathan R., Furlanetto, Steven R.

We examine the effect of Lyman continuum photons on the 21 cm background in the high-redshift universe. The brightness temperature of this transition is determined by the spin temperature T_s, which...

Cosmic Microwave Background Fluctuations from Gravitational Waves: An Analytic Approach (2004)

Pritchard, Jonathan R., Kamionkowski, Marc

We develop an analytic approach to calculation of the temperature and polarisation power spectra of the cosmic microwave background due to inflationary gravitational waves. This approach complements...