Matias Zaldarriaga

An improved method for 21-cm foreground removal (2009)

We show that the class of antenna layouts for telescope arrays allowing cheap analysis hardware (with cost scaling as N log N rather than N^2 with the number of antennae N) is encouragingly large,...

Liu, Adrian, Tegmark, Max, Bowman, Judd, Hewitt, Jacqueline, Zaldarriaga, Matias

21-cm tomography is expected to be difficult in part because of serious foreground contamination. Previous studies have found that line-of-sight approaches are capable of cleaning foregrounds to an...

New Perspective on Galaxy Clustering as a Cosmological Probe: General Relativistic Effects (2009)

Yoo, Jaiyul, Fitzpatrick, A. Liam, Zaldarriaga, Matias

We present a general relativistic description of galaxy clustering in a FLRW universe. The observed redshift and position of galaxies are affected by the matter fluctuations and the gravity waves...

Non-Gaussianities in Single Field Inflation and their Optimal Limits from the WMAP 5-year Data (2009)

Senatore, Leonardo, Smith, Kendrick M., Zaldarriaga, Matias

Using the recently developed effective field theory of inflation, we argue that the size and the shape of the non-Gaussianities generated by single-field inflation are generically well described by...

An Improved Method for 21cm Foreground Removal (2009)

Liu, Adrian, Tegmark, Max, Bowman, Judd, Hewitt, Jacqueline, Zaldarriaga, Matias

21 cm tomography is expected to be difficult in part because of serious foreground contamination. Previous studies have found that line-of-sight approaches are capable of cleaning foregrounds to an...

Observing the Evolution of the Universe (2009)

Aguirre, James, Amblard, Alexandre, Ashoorioon, Amjad, Baccigalupi, Carlo, Balbi, Amedeo, Bartlett, James, ...

How did the universe evolve? The fine angular scale (l>1000) temperature and polarization anisotropies in the CMB are a Rosetta stone for understanding the evolution of the universe. Through detailed...

Constraining a spatially dependent rotation of the Cosmic Microwave Background Polarization (2009)

Yadav, Amit P. S., Biswas, Rahul, Su, Meng, Zaldarriaga, Matias

Following Kamionkowski (2008), a quadratic estimator of the rotation of the plane of polarization of the CMB is constructed. This statistic can estimate a spatially varying rotation angle. We use...

Cosmology from the Highly-Redshifted 21 cm Line (2009)

Furlanetto, Steven, Lidz, Adam, Loeb, Abraham, McQuinn, Matthew, Pritchard, Jonathan, Shapiro, Paul, ...

One of the next decade's most exciting prospects is to explore the cosmic "dark ages," during which the first stars in the Universe formed, with the 21 cm line of neutral hydrogen. At z>6, this light...

Contributions to the Dark Matter 3-Pt Function from the Radiation Era (2009)

Fitzpatrick, A. Liam, Senatore, Leonardo, Zaldarriaga, Matias

We consider the contribution to the three-point function of matter density fluctuations from nonlinear growth after modes re-enter the horizon, and discuss effects that must be included in order to...

Astrophysics from the Highly-Redshifted 21 cm Line (2009)

Furlanetto, Steven, Lidz, Adam, Loeb, Abraham, McQuinn, Matthew, Pritchard, Jonathan, Aguirre, James, ...

The cosmic dark ages and the epoch of reionization, during which the first generations of stars and galaxies formed, are among the most compelling frontiers of extragalactic astrophysics and...

Optimal limits on f_{NL}^{local} from WMAP 5-year data (2009)

Smith, Kendrick M., Senatore, Leonardo, Zaldarriaga, Matias

We have applied the optimal estimator for f_{NL}^{local} to the 5 year WMAP data. Marginalizing over the amplitude of foreground templates we get -4 < f_{NL}^{local} < 80 at 95% CL. Error bars of...

Causality and Primordial Tensor Modes (2009)

Baumann, Daniel, Zaldarriaga, Matias

We introduce the real space correlation function of $B$-mode polarization of the cosmic microwave background (CMB) as a probe of superhorizon tensor perturbations created by inflation. By causality,...

Impact of Instrumental Systematic Contamination on the Lensing Mass Reconstruction using the CMB Polarization (2009)

Su, Meng, Yadav, Amit P. S., Zaldarriaga, Matias

In this paper, we study the effects of instrumental systematics on the reconstruction of the deflection angle power spectrum from weak lensing of Cosmic Microwave Background (CMB) temperature and...

Cosmological Perturbations at Second Order and Recombination Perturbed (2008)

Senatore, Leonardo, Tassev, Svetlin, Zaldarriaga, Matias

We derive the full set of second-order equations governing the evolution of cosmological perturbations, including the effects of the first-order electron number density perturbations, \delta_e. We...

Non-Gaussianities from Perturbing Recombination (2008)

Senatore, Leonardo, Tassev, Svetlin, Zaldarriaga, Matias

We approximately compute the bispectrum induced on the CMB by fluctuations in the standard recombination history. Of all the second order sources that can induce non-Gaussianity during recombination,...

CMBPol Mission Concept Study: Probing Inflation with CMB Polarization (2008)

Baumann, Daniel, Jackson, Mark G, Adshead, Peter, Amblard, Alexandre, Ashoorioon, Amjad, Bartolo, Nicola, ...

We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to...

CMBPol Mission Concept Study: A Mission to Map our Origins (2008)

Baumann, Daniel, Cooray, Asantha, Dodelson, Scott, Dunkley, Joanna, Fraisse, Aurélien A., Jackson, Mark G., ...

Quantum mechanical metric fluctuations during an early inflationary phase of the universe leave a characteristic imprint in the polarization of the cosmic microwave background (CMB). The amplitude of...

CMBPol Mission Concept Study: Reionization Science with the Cosmic Microwave Background (2008)

Zaldarriaga, Matias, Colombo, Loris, Komatsu, Eiichiro, Lidz, Adam, Mortonson, Michael, Oh, S. Peng, ...

We summarize existing constraints on the epoch of reionization and discuss the observational probes that are sensitive to the process. We focus on the role large scale polarization can play....

CMBPol Mission Concept Study: Probing Inflation with CMB Polarization (2008)

Baumann, Daniel, Jackson, Mark G., Adshead, Peter, Amblard, Alexandre, Ashoorioon, Amjad, Bartolo, Nicola, ...

We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to...

Will point sources spoil 21 cm tomography? (2008)

Liu, Adrian, Tegmark, Max, Zaldarriaga, Matias

21 cm tomography is emerging as a promising probe of the cosmological dark ages and the epoch of reionization, as well as a tool for observational cosmology in general. However, serious sources of...

HeII Reionization and its Effect on the IGM (2008)

McQuinn, Matthew, Lidz, Adam, Zaldarriaga, Matias, Hernquist, Lars, Hopkins, Philip F., Dutta, Suvendra, ...

Observations of the intergalactic medium (IGM) suggest that quasars reionize HeII in the IGM at z ~ 3. We have run a set of 190 and 430 comoving Mpc simulations of HeII being reionized by quasars to...

Probing Reionization with the 21 cm-Galaxy Cross Power Spectrum (2008)

Lidz, Adam, Zahn, Oliver, Furlanetto, Steven, McQuinn, Matthew, Hernquist, Lars, Zaldarriaga, Matias

The cross-correlation between high redshift galaxies and 21 cm emission from the high redshift intergalactic medium (IGM) promises to be an excellent probe of the Epoch of Reionization (EoR). On...

The Fast Fourier Transform Telescope (2008)

Improved estimation of cluster mass profiles from the cosmic microwave background (2008)

We propose an all-digital telescope for 21 cm tomography, which combines key advantages of both single dishes and interferometers. The electric field is digitized by antennas on a rectangular grid,...

Yoo, Jaiyul, Zaldarriaga, Matias

We develop a new method for reconstructing cluster mass profiles and large-scale structure from the cosmic microwave background (CMB). By analyzing the likelihood of CMB lensing, we analytically...

How accurately can 21 cm tomography constrain cosmology? (2008)

Mao, Yi, Tegmark, Max, McQuinn, Matthew, Zaldarriaga, Matias, Zahn, Oliver

There is growing interest in using 3-dimensional neutral hydrogen mapping with the redshifted 21 cm line as a cosmological probe, as it has been argued to have a greater long-term potential than the...

The Phase Transition to Eternal Inflation (2008)

Creminelli, Paolo, Dubovsky, Sergei, Nicolis, Alberto, Senatore, Leonardo, Zaldarriaga, Matias

For slow-roll inflation we study the phase transition to the eternal regime. Starting from a finite inflationary volume, we consider the volume of the universe at reheating as order parameter. We...

Detecting the Rise and Fall of 21 cm Fluctuations with the Murchison Widefield Array (2007)

Lidz, Adam, Zahn, Oliver, McQuinn, Matthew, Zaldarriaga, Matias, Hernquist, Lars

We forecast the sensitivity with which the Murchison Widefield Array (MWA) can measure the 21 cm power spectrum of cosmic hydrogen, using radiative transfer simulations to model reionization and the...

Probing the Neutral Fraction of the IGM with GRBs during the Epoch of Reionization (2007)

McQuinn, Matthew, Lidz, Adam, Zaldarriaga, Matias, Hernquist, Lars, Dutta, Suvendra

We show that near-infrared observations of the red side of the Ly-alpha line from a single gamma ray burst (GRB) afterglow cannot be used to constrain the global neutral fraction of the intergalactic...

Bumpy black holes from spontaneous Lorentz violation (2007)

Dubovsky, Sergei, Tinyakov, Peter, Zaldarriaga, Matias

We consider black holes in Lorentz violating theories of massive gravity. We argue that in these theories black hole solutions are no longer universal and exhibit a large number of hairs. If they...

Studying Reionization with Ly-alpha Emitters (2007)

McQuinn, Matthew, Hernquist, Lars, Zaldarriaga, Matias, Dutta, Suvendra

We show that observations of high-redshift Ly-alpha emitters (LAEs) have the potential to provide definitive evidence for reionization in the near future. Using 200 Mpc radiative transfer...

Quasar Proximity Zones and Patchy Reionization (2007)

Lidz, Adam, McQuinn, Matthew, Zaldarriaga, Matias, Hernquist, Lars, Dutta, Suvendra

Lyman-alpha forest absorption spectra towards quasars at z ~ 6 show regions of enhanced transmission close to their source. Several authors have argued that the apparently small sizes of these...

Algorithms for bispectra: forecasting, optimal analysis, and simulation (2006)

Smith, Kendrick M., Zaldarriaga, Matias

We propose a factorizability ansatz for angular bispectra which permits fast algorithms for forecasting, analysis, and simulation, yet is general enough to encompass many interesting CMB bispectra....

Limits on f_NL parameters from WMAP 3yr data (2006)

Creminelli, Paolo, Senatore, Leonardo, Zaldarriaga, Matias, Tegmark, Max

We analyze the 3-year WMAP data and look for a deviation from Gaussianity in the form of a 3-point function that has either of the two theoretically motivated shapes: local and equilateral. There is...

Eavesdropping on Radio Broadcasts from Galactic Civilizations with Upcoming Observatories for Redshifted 21cm Radiation (2006)

Loeb, Abraham, Zaldarriaga, Matias

The question of whether intelligent life exists elsewhere is one of the fundamental unknowns about our Universe. Over the past decade more than 200 extra-solar planets have been discovered, providing...

The morphology of HII regions during reionization (2006)

McQuinn, Matthew, Lidz, Adam, Zahn, Oliver, Dutta, Suvendra, Hernquist, Lars, Zaldarriaga, Matias

It is possible that the properties of HII regions during reionization depend sensitively on many poorly constrained quantities (the nature of the ionizing sources, the clumpiness of the gas in the...

Higher Order Contributions to the 21 cm Power Spectrum (2006)

Lidz, Adam, Zahn, Oliver, McQuinn, Matthew, Zaldarriaga, Matias, Dutta, Suvendra, Hernquist, Lars

We consider the contribution of 3rd and 4th order terms to the power spectrum of 21 cm brightness temperature fluctuations during the epoch of reionization, which arise because the 21 cm brightness...

A general solution to the E-B mixing problem (2006)

Smith, Kendrick M., Zaldarriaga, Matias

We derive a general ansatz for optimizing pseudo-C_l estimators used to measure CMB anisotropy power spectra, and apply it to the recently-proposed pure pseudo-C_l formalism, to obtain an estimator...

Estimators for local non-Gaussianities (2006)

Creminelli, Paolo, Senatore, Leonardo, Zaldarriaga, Matias

We study the Likelihood function of data given f_NL for the so-called local type of non-Gaussianity. In this case the curvature perturbation is a non-linear function, local in real space, of a...

Simulations and Analytic Calculations of Bubble Growth During Hydrogen Reionization (2006)

Zahn, Oliver, Lidz, Adam, McQuinn, Matthew, Dutta, Suvendra, Hernquist, Lars, Zaldarriaga, Matias, ...

We present results from a large volume simulation of Hydrogen reionization. We combine 3d radiative transfer calculations and an N-body simulation, describing structure formation in the intergalactic...

Task Force on Cosmic Microwave Background Research (2006)

Bock, James, Church, Sarah, Devlin, Mark, Hinshaw, Gary, Lange, Andrew, Lee, Adrian, ...

One of the most spectacular scientific breakthroughs in past decades was using measurements of the fluctuations in the cosmic microwave background (CMB) to test precisely our understanding of the...

Cosmological Parameter Estimation Using 21 cm Radiation from the Epoch of Reionization (2005)

McQuinn, Matthew, Zahn, Oliver, Zaldarriaga, Matias, Hernquist, Lars, Furlanetto, Steven R.

A number of radio interferometers are currently being planned or constructed to observe 21 cm emission from reionization. Not only will such measurements provide a detailed view of that epoch, but,...

Weak Gravitational Lensing of High-Redshift 21 cm Power Spectra (2005)

Mandel, Kaisey S., Zaldarriaga, Matias

We describe the effects of weak gravitational lensing by cosmological large scale structure on the diffuse emission of 21 centimeter radiation from neutral hydrogen at high redshifts during the era...

Lensing Reconstruction using redshifted 21cm Fluctuations (2005)

Zahn, Oliver, Zaldarriaga, Matias

We investigate the potential of second generation measurements of redshifted 21 cm radiation from before and during the epoch of reionization (EOR) to reconstruct the matter density fluctuations...

The Impact of Temperature Fluctuations on the Lyman-alpha Forest Power Spectrum (2005)

Lai, Kamson, Lidz, Adam, Hernquist, Lars, Zaldarriaga, Matias

We explore the impact of spatial fluctuations in the intergalactic medium temperature on the Lyman-alpha forest flux power spectrum near z ~ 3. We develop a semianalytic model to examine temperature...

Limits on non-Gaussianities from WMAP data (2005)

Creminelli, Paolo, Nicolis, Alberto, Senatore, Leonardo, Tegmark, Max, Zaldarriaga, Matias

We develop a method to constrain the level of non-Gaussianity of density perturbations when the 3-point function is of the "equilateral" type. Departures from Gaussianity of this form are produced by...

The Effects of Reionization on Lyman-alpha Galaxy Surveys (2005)

Furlanetto, Steven R., Zaldarriaga, Matias, Hernquist, Lars

Searches for Lyman-alpha emission lines are among the most effective ways to identify high-redshift galaxies. They are particularly interesting because they probe not only the galaxies themselves but...

On the stability of Dark Energy with Mass-Varying Neutrinos (2005)

Afshordi, Niayesh, Zaldarriaga, Matias, Kohri, Kazunori

An interesting dynamical model for dark energy which does not require extremely light scalar fields such as quintessence, and at the same time explains the (near-) coincidence between the neutrino...

The Kinetic Sunyaev-Zel'dovich Effect from Reionization (2005)

McQuinn, Matthew, Furlanetto, Steven R., Hernquist, Lars, Zahn, Oliver, Zaldarriaga, Matias

During the epoch of reionization, local variations in the ionized fraction (patchiness) imprint arcminute-scale temperature anisotropies in the CMB through the kinetic Sunyaev-Zel'dovich (kSZ)...

The Small-Scale Power Spectrum of Cold Dark Matter (2005)

Loeb, Abraham, Zaldarriaga, Matias

One of the best motivated hypotheses in cosmology states that most of the matter in the universe is in the form of weakly-interacting massive particles that decoupled early in the history of the...

The influence of non-uniform reionization on the CMB (2005)

Zahn, Oliver, Zaldarriaga, Matias, Hernquist, Lars, McQuinn, Matthew

We investigate the impact of spatial variations in the ionized fraction during reionization on temperature anisotropies in the CMB. We combine simulations of large scale structure to describe the...

Perturbations in bouncing cosmologies: dynamical attractor vs scale invariance (2004)

Creminelli, Paolo, Nicolis, Alberto, Zaldarriaga, Matias

For bouncing cosmologies such as the ekpyrotic/cyclic scenarios we show that it is possible to make predictions for density perturbations which are independent of the details of the bouncing phase....

Primordial Bispectrum Information from CMB Polarization (2004)

Babich, Daniel, Zaldarriaga, Matias

After the precise observations of the Cosmic Microwave Background (CMB) anisotropy power spectrum, attention is now being focused on the higher order statistics of the CMB anisotropies. Since linear...

Single field consistency relation for the 3-point function (2004)

Creminelli, Paolo, Zaldarriaga, Matias

We point out the existence of a consistency relation involving the 3-point function of scalar perturbations which is valid in any inflationary model, independently of the inflaton Lagrangian under...

Constraining the Topology of Reionization Through Lyman-alpha Absorption (2004)

Furlanetto, Steven, Hernquist, Lars, Zaldarriaga, Matias

The reionization of hydrogen in the intergalactic medium (IGM) is a crucial landmark in the history of the universe, but the processes through which it occurs remain mysterious. In particular, recent...

CMB 3-point functions generated by non-linearities at recombination (2004)

Creminelli, Paolo, Zaldarriaga, Matias

We study the 3-point functions generated at recombination in the squeezed triangle limit, when one mode has a wavelength much larger than the other two and is outside the horizon. The presence of the...

The shape of non-Gaussianities (2004)

Babich, Daniel, Creminelli, Paolo, Zaldarriaga, Matias

We study the dependence on configuration in momentum space of the primordial 3-point function of density perturbations in several different scenarios: standard slow-roll inflation, curvaton and...

Statistical Probes of Reionization With 21 cm Tomography (2004)

Furlanetto, Steven, Zaldarriaga, Matias, Hernquist, Lars

We consider the degree to which "21 cm tomography" of the high-redshift Universe can distinguish different ionization histories. Using a new analytic model for the size distribution of HII regions...

The Growth of HII Regions During Reionization (2004)

Furlanetto, Steven, Zaldarriaga, Matias, Hernquist, Lars

Recently, there has been a great deal of interest in understanding the reionization of hydrogen in the intergalactic medium (IGM). One of the major outstanding questions is how this event proceeds on...

Probing Primordial Non-Gaussianity with Large-Scale Structure (2003)

Scoccimarro, Roman, Sefusatti, Emiliano, Zaldarriaga, Matias

We consider primordial non-Gaussianity due to quadratic corrections in the gravitational potential parametrized by a non-linear coupling parameter fnl. We study constraints on fnl from measurements...

Ghost Inflation (2003)

Arkani-Hamed, Nima, Creminelli, Paolo, Mukohyama, Shinji, Zaldarriaga, Matias

We propose a new scenario for early cosmology, where an inflationary de Sitter phase is obtained with a ghost condensate. The transition to radiation dominance is triggered by the ghost itself,...

Measuring the Small-Scale Power Spectrum of Cosmic Density Fluctuations Through 21 cm Tomography Prior to the Epoch of Structure Formation (2003)

Loeb, Abraham, Zaldarriaga, Matias

The thermal evolution of the cosmic gas decoupled from that of the cosmic microwave background (CMB) at a redshift z~200. Afterwards and before the first stars had formed, the cosmic neutral hydrogen...

CMBfit: Rapid WMAP likelihood calculations with normal parameters (2003)

Sandvik, Havard B., Tegmark, Max, Wang, Xiaomin, Zaldarriaga, Matias

We present a method for ultra-fast confrontation of the WMAP cosmic microwave background observations with theoretical models, implemented as a publicly available software package called CMBfit,...

21 Centimeter Fluctuations from Cosmic Gas at High Redshifts (2003)

Zaldarriaga, Matias, Furlanetto, Steven, Hernquist, Lars

The relatively large Thomson optical depth, tau_e, inferred recently from the WMAP observations suggests that the Universe was reionized in a more complex manner than previously believed. However,...

Towards Constraints on Dark Energy from Absorption Spectra of Close Quasar Pairs (2003)

Lidz, Adam, Hui, Lam, Crotts, Arlin P. S., Zaldarriaga, Matias

A comparison between the line of sight power spectrum of absorption in the Lyman-alpha forest and the cross power spectrum between the absorption in neighboring lines of sight offers an...

The significance of the largest scale CMB fluctuations in WMAP (2003)

Tegmark, Max, Zaldarriaga, Matias, Hamilton, Andrew

We investigate anomalies reported in the Cosmic Microwave Background maps from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite on very large angular scales and discuss possible...

Non-Gaussianities in models with a varying inflaton decay rate (2003)

Cosmological Perturbations From Inhomogeneous Reheating, Freeze-Out, and Mass Domination (2003)

We consider the expected level of primordial non-Gaussianities in models in which density perturbations are produced by spatial fluctuations in the decay rate of the inflaton. We consider both the...

Dvali, Gia, Gruzinov, Andrei, Zaldarriaga, Matias

We generalize a recently proposed mechanism for the origin of primordial metric perturbations in inflationary models. Quantum fluctuations of light scalar fields during inflation give rise to...

The Polarization of the Cosmic Microwave Background (2003)

A new mechanism for generating density perturbations from inflation (2003)

We summarize the physical mechanism by which the Cosmic Microwave Background acquires a small degree of polarization. We discuss the imprint left by gravitational waves and the use of polarization as...

Dvali, Gia, Gruzinov, Andrei, Zaldarriaga, Matias

We propose a new mechanism to generate density perturbations in inflationary models. Spatial fluctuations in the decay rate of the inflaton field to ordinary matter lead to fluctuations in the...

The last stand before MAP: cosmological parameters from lensing, CMB and galaxy clustering (2002)

Wang, Xiaomin, Tegmark, Max, Jain, Bhuvnesh, Zaldarriaga, Matias

Cosmic shear measurements have now improved to the point where they deserve to be treated on par with CMB and galaxy clustering data for cosmological parameter analysis, using the full measured...

Probing the Friedmann equation during recombination with future CMB experiments (2002)

Zahn, Oliver, Zaldarriaga, Matias

We show that by combining measurements of the temperature and polarization anisotropies of the Cosmic Microwave Background (CMB), future experiments will tightly constrain the expansion rate of the...

The end of unified dark matter? (2002)

Sandvik, Havard, Tegmark, Max, Zaldarriaga, Matias, Waga, Ioav

Despite the interest in dark matter and dark energy, it has never been shown that they are in fact two separate substances. We provide the first strong evidence that they are separate by ruling out a...

The Accelerated Universe and the Moon (2002)

Dvali, Gia, Gruzinov, Andrei, Zaldarriaga, Matias

Cosmologically motivated theories that explain small acceleration rate of the Universe via modification of gravity at very large, horizon or super-horizon distances, can be tested by precision...

Benchmark Parameters for CMB Polarization Experiments (2002)

Hu, Wayne, Hedman, Matthew M., Zaldarriaga, Matias

The recently detected polarization of the cosmic microwave background (CMB) holds the potential for revealing the physics of inflation and gravitationally mapping the large-scale structure of the...

The Far-Infrared Background Correlation with CMB Lensing (2002)

Song, Yong-Seon, Cooray, Asantha, Knox, Lloyd, Zaldarriaga, Matias

The intervening large--scale structure distorts cosmic microwave background (CMB) anisotropies via gravitational lensing. The same large--scale structure, traced by dusty star--forming galaxies, also...

Higher-order moments of the lensing shear and other spin two fields (2002)

Zaldarriaga, Matias, Scoccimarro, Roman

We present a method for defining higher-order moments of a spin-2 field on the sky using the transformation properties of these statistics under rotation and parity. For the three-point function of...

E/B decomposition of finite pixelized CMB maps (2002)

Bunn, Emory F., Zaldarriaga, Matias, Tegmark, Max

Separation of the E and B components of a microwave background polarization map or a weak lensing map is an essential step in extracting science from it, but when the map covers only part of the sky...

Separating the Early Universe from the Late Universe: cosmological parameter estimation beyond the black box (2002)

First attempt at measuring the CMB cross-polarization (2002)

We present a method for measuring the cosmic matter budget without assumptions about speculative Early Universe physics, and for measuring the primordial power spectrum P*(k) non-parametrically,...

Tegmark, Max, Zaldarriaga, Matias, Barkats, Denis, Gundersen, Josh O., Hedman, Matt M., ...

We compute upper limits on CMB cross-polarization by cross-correlating the PIQUE and Saskatoon experiments. We also discuss theoretical and practical issues relevant to measuring cross-polarization...

Supernovae, CMB, and Gravitational Leakage into Extra Dimensions (2002)

Deffayet, Cédric, Landau, Susana J., Raux, Julien, Zaldarriaga, Matias, Astier, Pierre

We discuss observational constraints coming from CMB and type Ia supernovae, for the model of accelerated universe produced by gravitational leakage into extra dimensions. Our fits indicate that the...

Takemi Okamoto (2002)

Wayne Hu, Matt Hedman, Joe Silk, Martin White, Matias Zaldarriaga, Matt Hedman, ...

• Damping tail of temperature power spectrum and its use as a standard ruler • Generation of polarization through damping • Unveiling of gravitational lensing from features in the damping tail...

Dimming of Supernovae by Photon-Pseudoscalar Conversion and the Intergalactic Plasma (2001)

Deffayet, Cédric, Harari, Diego, Uzan, Jean-Philippe, Zaldarriaga, Matias

Recently Csaki, Kaloper and Terning (hep-ph/0111311) suggested that the observed dimming of distant type Ia supernovae may be a consequence of mixing of the photons with very light axions. We point...

How Neutral is the Intergalactic Medium at z ~ 6? (2001)

Lidz, Adam, Hui, Lam, Zaldarriaga, Matias, Scoccimarro, Roman

Recent observations of high redshift quasar spectra reveal long gaps with little flux. A small or no detectable flux does not by itself imply the intergalactic medium (IGM) is neutral. Inferring the...

Inferring the Linear Power Spectrum from the Lyman-alpha Forest (2001)

Zaldarriaga, Matias, Scoccimarro, Roman, Hui, Lam

We discuss the determination of the linear power spectrum of dark matter fluctuations from measurements of the transmitted flux Ly-alpha Forest power spectrum. We show that at most scales probed by...

Changing alpha With Time: Implications For Fifth-Force-Type Experiments And Quintessence (2001)

Dvali, Gia, Zaldarriaga, Matias

If the recent observations suggesting a time variation of the fine structure constant are correct, they imply the existence of an ultra light scalar particle. This particle inevitably couples to...

The nature of the E-B decomposition of CMB polarization (2001)

The Imprint of Lithium Recombination on the Microwave Background Anisotropies (2001)

We present a derivation of the transformation between the Q and U Stokes parameters and the E and B scalar and pseudo-scalar fields. We emphasize the geometrical properties that such transformation...

Zaldarriaga, Matias, Loeb, Abraham

Following Loeb (2001), we explore the imprint of the resonant 6708A line opacity of neutral lithium on the temperature and polarization anisotropies of the cosmic microwave background (CMB) at...

Is cosmology consistent? (2001)

Wang, Xiaomin, Tegmark, Max, Zaldarriaga, Matias

We perform a detailed analysis of the latest CMB measurements (including BOOMERaNG, DASI, Maxima and CBI), both alone and jointly with other cosmological data sets involving, e.g., galaxy clustering...

The Cosmic Baryon Fraction and the Extragalactic Ionizing Background (2001)

Hui, Lam, Haiman, Zoltan, Zaldarriaga, Matias, Alexander, Tal

We reassess constraints on the cosmological baryon density from observations of the mean decrement and power spectrum of the Lyman-alpha forest, taking into account uncertainties in all free...

Searching for fluctuations in the IGM temperature using the Lyman alpha forest (2001)

Constraints from the Lyman alpha forest power spectrum (2000)

We propose a statistical method to search for fluctuations in the temperature of the intergalactic medium (IGM) using the Lyman $\alpha$ forest. The power on small scales ($\sim 25 \km/\s$) is used...

Zaldarriaga, Matias, Hui, Lam, Tegmark, Max

We use published measurements of the transmission power spectrum of the Lyman alpha forest to constrain several parameters that describe cosmology and thermal properties of the intergalactic medium...

Constraining non standard recombination: A worked example (2000)

Landau, Susana, Harari, Diego, Zaldarriaga, Matias

We fit the BOOMERANG, MAXIMA and COBE/DMR measurements of the cosmic microwave background anisotropy in spatially flat cosmological models where departures from standard recombination of the primeval...

Latest cosmological constraints on the densities of hot and cold dark matter (2000)

Tegmark, Max, Zaldarriaga, Matias, Hamilton, Andrew J. S.

As experimentalists step up their pursuit of cold dark matter particles and neutrino masses, cosmological constraints are tightening. We compute the joint constraints on 11 cosmological parameters...

Towards a refined cosmic concordance model: joint 11-parameter constraints from CMB and large-scale structure (2000)

Tegmark, Max, Zaldarriaga, Matias, Hamilton, Andrew J. S.

We present a method for calculating large numbers of power spectra C_l and P(k) that accelerates CMBfast by a factor around 10^3 without appreciable loss of accuracy, then apply it to constrain 11...

Correlations in the Lyman alpha forest: testing the gravitational instability paradigm (2000)

Zaldarriaga, Matias, Seljak, Uros, Hui, Lam

We investigate correlations between the long wavelength fluctuations and the small scale power in the Lyman alpha forest. We show that such correlations can be used to discriminate between...

CMB Observables and Their Cosmological Implications (2000)

Hu, Wayne, Fukugita, Masataka, Zaldarriaga, Matias, Tegmark, Max

We show that recent measurements of the power spectrum of cosmic microwave background anisotropies by BOOMERanG and MAXIMA can be characterized by four observables, the position of the first acoustic...

New CMB constraints on the cosmic matter budget: trouble for nucleosynthesis? (2000)

Current cosmological constraints from a 10 parameter CMB analysis (2000)

We compute the joint constraints on ten cosmological parameters from the latest CMB measurements. The lack of a significant second acoustic peak in the latest Boomerang and Maxima data favors models...

Wayne Hu, Masataka Fukugita, Matias Zaldarriaga, Max Tegmark

We compute the constraints on a ``standard'' 10 parameter cold dark matter (CDM) model from the most recent CMB and data and other observations, exploring 30 million discrete models and two...

We show that recent measurements of the power spectrum of cosmic microwave background anisotropies by Boomerang and MAXIMA can be mainly characterized by four observables: the position of the Ðrst...

Lensing effect on polarization in microwave background: extracting convergence power spectrum (1999)

Guzik, Jacek, Seljak, Uros, Zaldarriaga, Matias

Matter inhomogeneities along the line of sight deflect the cosmic microwave background (CMB) photons originating at the last scattering surface at redshift $z \sim 1100$. These distortions modify the...

Correlations in the Spatial Power Spectrum Inferred from Angular Clustering: Methods and Application to APM (1999)

Eisenstein, Daniel J., Zaldarriaga, Matias

We reconsider the inference of spatial power spectra from angular clustering data and show how to include correlations in both the angular correlation function and the spatial power spectrum....

CMBFAST for spatially closed universes (1999)

Lensing of the CMB: Non Gaussian aspects (1999)

We extend the cosmological linear perturbation theory code CMBFAST to closed geometries. This completes the implementation of CMBFAST to all types of geometries and allows the user to perform an...

Lensing Induced Cluster Signatures in Cosmic Microwave Background (1999)

We study the generation of CMB anisotropies by gravitational lensing on small angular scales. We show these fluctuations are not Gaussian. We prove that the power spectrum of the tail of the CMB...

Power Spectrum Correlations Induced by Non-Linear Clustering (1999)

We show that clusters of galaxies induce step-like wiggles on top of the cosmic microwave background (CMB). The direction of the wiggle is parallel to the large scale gradient of CMB allowing one to...

Scoccimarro, Roman, Zaldarriaga, Matias, Hui, Lam

Gravitational clustering is an intrinsically non-linear process that generates significant non-Gaussian signatures in the density field. We consider how these affect power spectrum determinations...

Direct Signature of Evolving Gravitational Potential from Cosmic Microwave Background (1998)

Reconstructing Projected Matter Density from Cosmic Microwave Background (1998)

We show that time dependent gravitational potential can be directly detected from the cosmic microwave background (CMB) anisotropies. The signature can be measured by cross-correlating the CMB with...

Measuring Dark Matter Power Spectrum from Cosmic Microwave Background (1998)

Gravitational lensing distorts the cosmic microwave background (CMB) anisotropies and imprints a characteristic pattern onto it. The distortions depend on the projected matter density between today...

Fluctuations in the Cosmic Microwave Background (1998)

We propose a method to extract the projected power spectrum of density perturbations from the distortions in the cosmic microwave background (CMB). The distortions are imprinted onto the CMB by the...

Polarization of Microwave Background: Statistical and Physical Properties (1998)

In this thesis we investigate several aspects related to the theory of fluctuations in the Cosmic Microwave Background. We develop a new algorithm to calculate the angular power spectrum of the...

Gravitational Lensing Effect on Cosmic Microwave Background Polarization (1998)

We discuss statistical and physical properties of cosmic microwave background polarization, both in Fourier and in real space. The latter allows for a more intuitive understanding of some of the...

CMB Polarization Experiments (1997)

We investigate the effect of gravitational lensing by matter distribution in the universe on the cosmic microwave background (CMB) polarization power spectra and temperature-polarization...

A Complete Treatment of CMB Anisotropies in a FRW Universe (1997)

We discuss the analysis of polarization experiments with particular emphasis on those that measure the Stokes parameters on a ring on the sky. We discuss the ability of these experiments to separate...

Hu, Wayne, Seljak, Uros, White, Martin, Zaldarriaga, Matias

We generalize the total angular momentum method for computing Cosmic Microwave Background anisotropies to Friedman-Robertson-Walker (FRW) spaces with arbitrary geometries. This unifies the treatment...

CMB polarization as a direct test of Inflation (1997)

Spergel, David N., Zaldarriaga, Matias

We study the auto-correlation function of CMB polarization anisotropies and their cross correlation with temperature fluctuations as probe of the causal structure of the universe. Because...

Integral Solution for the Microwave Background Anisotropies in Non-fl at Universes (1997)

Zaldarriaga, Matias, Seljak, Uros, Bertschinger, Edmund

We present an efficient method to compute CMB anisotropies in non-flat universes. First we derive the Boltzmann equation for cosmic microwave background temperature and polarization fluctuations...

An All-Sky Analysis of Polarization in the Microwave Background (1996)

Signature of Gravity Waves in Polarization of the Microwave Background (1996)

Using the formalism of spin-weighted functions we present an all-sky analysis of polarization in the Cosmic Microwave Background (CMB). Linear polarization is a second-rank symmetric and traceless...

Depolarization of the cosmic microwave background by a primordial magnetic field and its effect upon temperature anisotropy (1996)

Using spin-weighted decomposition of polarization in the Cosmic Microwave Background (CMB) we show that a particular combination of Stokes $Q$ and $U$ parameters vanishes for primordial fluctuations...

Harari, Diego, Hayward, Justin, Zaldarriaga, Matias

We estimate the depolarizing effect of a primordial magnetic field upon the cosmic microwave background radiation due to differential Faraday rotation across the last scattering surface. The degree...

Polarization of the Microwave Background in Reionized Models (1996)

A Line of Sight Approach to Cosmic Microwave Background Anisotropies (1996)

I discuss the physics of polarization in models with early reionization. For sufficiently high optical depth to recombination the polarization is boosted on large scales while it is suppressed on...