Projected Constraints on Modified Gravity Cosmologies from 21cm Intensity Mapping (2009)
Masui, Kiyoshi Wesley, Schmidt, Fabian, Pen, Ue-Li, McDonald, Patrick
We present projected constraints on modified gravity models from the observational technique known as 21cm intensity mapping, where cosmic structure is detected without resolving individual galaxies....
I show how to reintroduce velocity dispersion into perturbation theory (PT) calculations of structure in the Universe, i.e., how to go beyond the pressureless fluid approximation, starting from first...
I extend the usual linear-theory formula for large-scale clustering in redshift-space to include gravitational redshift. The extra contribution to the standard galaxy power spectrum is suppressed by...
Probing the Epoch of Reionization with the Lyman Alpha Forest at z~4-5 (2009)
Cen, Renyue, McDonald, Patrick, Trac, Hy, Loeb, Abraham
The inhomogeneous cosmological reionization process leaves tangible imprints in the intergalactic medium down to z=4-5. The Lyman-alpha forest flux power spectrum provides a potentially powerful...
One-Loop Renormalization of the Electroweak Sector with Lorentz Violation (2009)
Colladay, Don, McDonald, Patrick
The one-loop renormalizability of the electroweak sector of the Standard Model Extension with Lorentz violation is studied. Functional determinants are used to calculate the one-loop contributions of...
Clustering of dark matter tracers: generalizing bias for the coming era of precision LSS (2009)
McDonald, Patrick, Roy, Arabindo
On very large scales, density fluctuations in the Universe are small, suggesting a perturbative model for large-scale clustering of galaxies (or other dark matter tracers), in which the galaxy...
How to measure redshift-space distortions without sample variance (2008)
McDonald, Patrick, Seljak, Uros
We show how to use multiple tracers of large-scale density with different biases to measure the redshift-space distortion parameter beta=f/b=(dlnD/dlna)/b (where D is the growth rate and a the...
On measuring the gravitational-wave background using Pulsar Timing Arrays (2008)
Van Haasteren, Rutger, Levin, Yuri, McDonald, Patrick, Lu, Tingting
Long-term precise timing of Galactic millisecond pulsars holds great promise for measuring the long-period (months-to-years) astrophysical gravitational waves. Several gravitational-wave...
Primordial non-Gaussianity: large-scale structure signature in the perturbative bias model (2008)
I compute the effect on the power spectrum of tracers of the large-scale mass-density field (e.g., galaxies) of primordial non-Gaussianity of the form Phi=phi+fNL (phi-)+gNL phi^3+..., where Phi is...
One-Loop Renormalization of QCD with Lorentz Violation (2007)
Colladay, Don, McDonald, Patrick
The explicit one-loop renormalizability of the gluon sector of QCD with Lorentz violation is demonstrated. The result is consistent with multiplicative renormalization as the required counter terms...
Iliev, Ilian T., Shapiro, Paul R., McDonald, Patrick, Mellema, Garrelt, Pen, Ue-Li
Observations of high-redshift Ly-alpha sources are a major tool for studying the high-redshift Universe. We discuss the effect of the reionizing intergalactic medium on the observability of Ly-alpha...
Reionization: Characteristic Scales, Topology and Observability (2007)
Iliev, Ilian T., Shapiro, Paul R., Mellema, Garrelt, Pen, Ue-Li, McDonald, Patrick, Alvarez, Marcelo A.
Recently the numerical simulations of the process of reionization of the universe at z>6 have made a qualitative leap forward, reaching sufficient sizes and dynamic range to determine the...
Baryon Acoustic Oscillation Intensity Mapping as a Test of Dark Energy (2007)
Chang, Tzu-Ching, Pen, Ue-Li, Peterson, Jeffrey B., McDonald, Patrick
The expansion of the universe appears to be accelerating, and the mysterious anti-gravity agent of this acceleration has been called ``dark energy''. To measure the dynamics of dark energy, Baryon...
Simulating Reionization: Character and Observability (2007)
Iliev, Ilian T., Shapiro, Paul R., Mellema, Garrelt, Pen, Ue-Li, McDonald, Patrick, Bond, J. Richard
In recent years there has been considerable progress in our understanding of the nature and properties of the reionization process. In particular, the numerical simulations of this epoch have made a...
Inverse problems for random walks on trees: network tomography (2006)
De La Pena, Victor, Gzyl, Henryk, McDonald, Patrick
Let $G$ be a finite tree with root $r$ and associate to the internal vertices of $G$ a collection of transition probabilities for a simple nondegenerate Markov chain. Embedd $G$ into a graph...
Clustering of dark matter tracers: renormalizing the bias parameters (2006)
A commonly used perturbative method for computing large-scale clustering of tracers of mass density, like galaxies, is to model the tracer density field as a Taylor series in the local smoothed mass...
One-Loop Renormalization of Pure Yang-Mills with Lorentz Violation (2006)
Colladay, Don, McDonald, Patrick
The explicit one-loop renormalizability of pure Yang-Mills theory with Lorentz violation is demonstrated. The result is consistent with multiplicative renormalization as the required counter terms...
McDonald, Patrick, Eisenstein, Daniel
We explore the requirements for a Lyman-alpha forest (LyaF) survey designed to measure the angular diameter distance and Hubble parameter at 2~
Dark matter clustering: a simple renormalization group approach (2006)
I compute a renormalization group (RG) improvement to the standard beyond-linear-order Eulerian perturbation theory (PT) calculation of the power spectrum of large-scale density fluctuations in the...
There's a Bug in Your Head (2006)
Hastings Center Report - Volume 36, Number 3, May-June 2006
Seljak, Uros, Slosar, Anze, McDonald, Patrick
We combine the Ly-alpha forest power spectrum (LYA) from the Sloan Digital Sky Survey (SDSS) and high resolution spectra with cosmic microwave background (CMB) including 3-year WMAP, and supernovae...
Can sterile neutrinos be the dark matter? (2006)
Seljak, Uros, Makarov, Alexey, McDonald, Patrick, Trac, Hy
We use the Ly-alpha forest power spectrum measured by the SDSS and high-resolution spectroscopy observations in combination with cosmic microwave background and galaxy clustering constraints to place...
Bose-Einstein Condensates as a Probe for Lorentz Violation (2006)
Colladay, Don, McDonald, Patrick
The effects of small Lorentz-violating terms on Bose-Einstein condensates are analyzed. We find that there are changes to the phase and shape of the ground-state wave function that vary with the...
Dependence of the non-linear mass power spectrum on the equation of state of dark energy (2005)
McDonald, Patrick, Trac, Hy, Contaldi, Carlo
We present N-body simulation calculations of the dependence of the power spectrum of non-linear cosmological mass density fluctuations on the equation of state of the dark energy, w=p/rho. At fixed...
Colladay, Don, McDonald, Patrick
In this talk, instantons are discussed in the presence of Lorentz violation. Conventional topological arguments are applied to classify the modified solutions to the Yang-Mills equations according to...
Nonrelativisitic Ideal Gasses and Lorentz Violations (2004)
Colladay, Don, McDonald, Patrick
We develop statistical mechanics for a nonrelativisitic ideal gas in the presence of Lorentz violating background fields. The analysis is performed using the Standard-Model Extension (SME). We derive...
Statistical Mechanics and Lorentz Violation (2004)
Colladay, Don, McDonald, Patrick
The theory of statistical mechanics is studied in the presence of Lorentz-violating background fields. The analysis is performed using the Standard-Model Extension (SME) together with a Jaynesian...
The Lyman-alpha Forest Power Spectrum from the Sloan Digital Sky Survey (2004)
McDonald, Patrick, Seljak, Uros, Burles, Scott, Schlegel, David J., Weinberg, David H., Shih, David, ...
We measure the power spectrum, P_F(k,z), of the transmitted flux in the Ly-alpha forest using 3035 high redshift quasar spectra from the Sloan Digital Sky Survey. This sample is almost two orders of...
Weak lensing and CMB: Parameter forecasts including a running spectral index (2004)
Ishak, Mustapha, Hirata, Christopher M., McDonald, Patrick, Seljak, Uroš
We use statistical inference theory to explore the constraints from future galaxy weak lensing (cosmic shear) surveys combined with the current CMB constraints on cosmological parameters, focusing...
Weak Lensing and CMB: Parameter forecasts including a running spectral index (2003)
Ishak, Mustapha, Hirata, Christopher M., McDonald, Patrick, Seljak, Uros
We use statistical inference theory to explore the constraints from future galaxy weak lensing (cosmic shear) surveys combined with the current CMB constraints on cosmological parameters, focusing...
Schirber, Michael, Miralda-Escude, Jordi, McDonald, Patrick
The transverse proximity effect is the expected decrease in the strength of the Lya forest absorption in a QSO spectrum when another QSO lying close to the line of sight enhances the photoionization...
Cosmological constraints from the CMB and Ly-alpha forest revisited (2003)
Seljak, Uros, McDonald, Patrick, Makarov, Alexey
The WMAP team has recently highlighted the usefulness of combining the Ly-alpha forest constraints with those from the cosmic microwave background (CMB). This combination is particularly powerful as...
Constraining the dark energy with Ly-alpha forest (2002)
Seljak, Uros, Mandelbaum, Rachel, McDonald, Patrick
Statistical properties of gas absorption in high redshift quasars such as power spectrum and bispectrum allow one to determine the evolution of structure over the redshift range 22. In combination...
Moment Problems and the Causal Set Approach to Quantum Gravity (2002)
We study a collection of discrete Markov chains related to the causal set approach to modeling discrete theories of quantum gravity. The transition probabilities of these chains satisfy a general...
Diffusions on Graphs, Poisson Problems and Spectral Geometry (2002)
McDonald, Patrick, Meyers, Robert
We study diffusions, variational principles and associated boundary value problems on directed graphs with natural weightings. Using random walks and exit times, we associate to certain subgraphs...
Dirichlet Spectrum and Heat Content (2002)
McDonald, Patrick, Meyers, Robert
Let $M$ be a complete Riemannian manifold and $D\subset M$ a smoothly bounded domain with compact closure. We use Brownian motion and the classic results on the Stieltjes moment problem to study the...
Redefining Spinors in Lorentz-Violating QED (2002)
Colladay, Don, McDonald, Patrick
An analysis of spinor redefinitions in the context of the Lorentz-violating QED extension is performed. Certain parameters that apparently violate Lorentz invariance are found to be physically...
Large-scale Correlation of Mass and Galaxies with the Lyman-alpha Forest Transmitted Flux (2001)
McDonald, Patrick, Miralda-Escudé, Jordi, Cen, Renyue
We present predictions of the correlation between the Lyman-alpha forest absorption in quasar spectra and the mass within \sim 5 Mpc/h (comoving) of the line of sight, using fully hydrodynamic and...
Cen, Renyue, McDonald, Patrick
The temporal evolution of the ionizing UV background radiation field at high redshift provides a probe of the evolution of the early star formation rate. By comparing the observed levels of...
The correlation between Lyman-alpha absorption in the spectra of quasar pairs can be used to measure the transverse distance scale at z~2, which is sensitive to the cosmological constant...
Cosmic Microwave Background constraint on residual annihilations of relic particles (2000)
McDonald, Patrick, Scherrer, Robert J., Walker, Terry P.
Energy injected into the Cosmic Microwave Background at redshifts z
McDonald, Patrick, Miralda-Escude, Jordi
We use the redshift evolution of the lyman-alpha forest mean transmitted flux at z>2.5 to infer the evolution of the intensity of the ionizing background, using theoretical predictions for the...
McDonald, Patrick, Miralda-Escude, Jordi, Rauch, Michael, Sargent, Wallace L. W., Barlow, Tom A., Cen, Renyue
The evolution of the temperature in the intergalactic medium is related to the reionization of hydrogen and helium, and has important consequences for our understanding of the Lya forest and of...
McDonald, Patrick, Miralda-Escude, Jordi, Rauch, Michael, Sargent, Wallace L. W., Barlow, Tom A., Cen, Renyue, ...
A sample of eight quasars observed at high resolution and signal-to-noise is used to determine the probability distribution function (PDF), the power spectrum, and the correlation function of the...
Galaxy Formation and the Kinematics of Damped Lyman Alpha Systems (1998)
McDonald, Patrick, Miralda-Escude, Jordi
A model of damped lyman alpha systems is presented based on randomly moving clouds in spherical halos. We use the Press-Schechter model for the abundance of halos, and assume that each halo has a...
Measuring the Cosmological Geometry from the Lyman Alpha Forest along Parallel Lines of Sight (1998)
McDonald, Patrick, Miralda-Escude, Jordi
We discuss the feasibility of measuring the cosmological metric using the redshift space correlation function of the Lya forest in multiple lines of sight, as a function of angular and velocity...
Isoperimetric Conditions And Diffusions In Riemannian Manifolds (1998)
. We study diffusions in Riemannian manifolds and properties of their exit time moments from smoothly bounded domains with compact closure. For any smoothly bounded domain with compact closure,\Omega...
Regulation of leukotriene synthesis [microforme] / (1993)
Les ch. 1-8 rédigés par l'auteur et collab. en anglais avec résumés en français et en anglais ont été ou seront publiés dans différents titres de périodiques.
Regulation of leukotriene synthesis / (1993)
Les ch. 1-8 rédigés par l'auteur et collab. en anglais avec résumés en français et en anglais ont été ou seront publiés dans différents titres de périodiques.
Abstraction ou intuition / (1962)
Thèse (Licence)--Université de Montréal, 1962.
Abstraction ou intuition [microforme] / (1962)
Thèse (Licence)--Université de Montréal, 1962.
Inverse problems for random walks on trees: Network tomography
De La Pena, Victor, Gzyl, Henryk, McDonald, Patrick
We solve a natural inverse problem for transition probabilities for Markov chains on rooted trees using hitting time distribution for leaves. Our solution is algorithmic and the natural statistics...