Constraining Modified Gravity and Growth with Weak Lensing (2008)
Thomas, Shaun A., Abdalla, Filipe B., Weller, Jochen
The idea that we live in a Universe undergoing a period of acceleration is a strongly held notion in cosmology. As this can, potentially, be explained with a modification to General Relativity we...
Deconstructing Baryon Acoustic Oscillations: A Comparison of Methods (2008)
Rassat, Anais, Amara, Adam, Amendola, Luca, Castander, Francisco J., Kitching, Thomas, Kunz, Martin, ...
The Baryon Acoustic Oscillations (BAOs) or baryon wiggles which are present in the galaxy power spectrum at scales 100-150Mpc/h are powerful features with which to constrain cosmology. The potential...
Complementarity of Future Dark Energy Probes (2008)
Tang, Jiayu, Abdalla, Filipe B., Weller, Jochen
In recent years a plethora of future surveys have been suggested to constrain the nature of dark energy. In this paper we adapt a binning approach to the equation of state factor ``w'' and discuss...
Accurate Realizations of the Ionized Gas in Galaxy Clusters: Calibrating Feedback (2006)
Bode, Paul, Ostriker, Jeremiah P., Weller, Jochen, Shaw, Laurie
Using the full, three-dimensional potential of galaxy cluster halos (drawn from an N-body simulation of the current, most favored cosmology), the distribution of the X-ray emitting gas is found by...
Probing Modified Gravity by Combining Supernovae and Galaxy Cluster Surveys (2006)
Tang, Jia-Yu, Weller, Jochen, Zablocki, Alan
Possible explanations of the observed accelerated expansion of the Universe are the introduction of a dark energy component or the modifications of gravity at large distances. A particular difference...
The Cosmic Microwave Background and the Ionization History of the Universe (2006)
Lewis, Antony, Weller, Jochen, Battye, Richard
Details of how the primordial plasma recombined and how the universe later reionized are currently somewhat uncertain. This uncertainty can restrict the accuracy of cosmological parameter...
Constraining Inverse Curvature Gravity with Supernovae (2005)
Mena, Olga, Santiago, Jose, Weller, Jochen
We show that the current accelerated expansion of the Universe can be explained without resorting to dark energy. Models of generalized modified gravity, with inverse powers of the curvature can have...
Dark Energy Studies: Challenges to Computational Cosmology (2005)
Annis, James, Castander, Francisco J., Evrard, August E., Frieman, Joshua A., Gaztanaga, Enrique, Jain, Bhuvnesh, ...
The ability to test the nature of dark mass-energy components in the universe through large-scale structure studies hinges on accurate predictions of sky survey expectations within a given world...
Constraining Dark Energy with the Dark Energy Survey: Theoretical Challenges (2005)
Annis, James, Bridle, Sarah, Castander, Francisco J., Evrard, August E., Fosalba, Pablo, Frieman, Joshua A., ...
The Dark Energy Survey (DES) will use a new imaging camera on the Blanco 4-m telescope at CTIO to image 5000 square degrees of sky in the South Galactic Cap in four optical bands, and to carry out...
Optimizing the yield of Sunyaev-Zel'dovich cluster surveys (2004)
Battye, Richard A., Weller, Jochen
We consider the optimum depth of a cluster survey selected using the Sunyaev-Zel'dovich effect. By using simple models for the evolution of the cluster mass function and detailed modeling for a...
Rapetti, David, Allen, Steven W., Weller, Jochen
We present new constraints on the evolution of dark energy from an analysis of Cosmic Microwave Background, supernova and X-ray galaxy cluster data. Our analysis employs a minimum of priors and...
Viel, Matteo, Weller, Jochen, Haehnelt, Martin
The combined analysis of the cosmic microwave background on large scales and Lyman-alpha forest on small scales provides a sufficiently long lever arm to obtain strong constraints on the slope and...
Fast Identification of Bound Structures in Large N-body Simulations (2004)
Weller, Jochen, Ostriker, Jeremiah P, Bode, Paul, Shaw, Laurie
We present an algorithm which is designed to allow the efficient identification and preliminary dynamical analysis of thousands of structures and substructures in large N-body simulations. First we...
Neutral hydrogen surveys for high redshift galaxy clusters and proto-clusters (2004)
Battye, Richard A., Davies, Rod D., Weller, Jochen
We discuss the possibility of performing blind surveys to detect large-scale features of the universe using 21cm emission. Using instruments with approx. 5'-10' resolution currently in the planning...
Constraining cosmological parameters using Sunyaev-Zel'dovich cluster surveys (2003)
Battye, Richard A., Weller, Jochen
We discuss how future cluster surveys can constrain cosmological parameters with particular reference to the properties of the dark energy component responsible for the observed acceleration of the...
Sunyaev-Zel'dovich cluster surveys using a large beam (2003)
Battye, Richard A., Weller, Jochen
Sunyaev Zel'dovich cluster surveys can be used to constrain cosmological parameters. Extracting clusters from the primary anisotropies and the unresolved background from very faint clusters is simple...
Constraining dark energy with Sunyaev-Zel'dovich cluster surveys (2001)
Weller, Jochen, Battye, Richard, Kneissl, Ruediger
We discuss the prospects of constraining the properties of a dark energy component, with particular reference to a time varying equation of state, using future cluster surveys selected by their...
Future Supernovae observations as a probe of dark energy (2001)
Weller, Jochen, Albrecht, Andreas
We study the potential impact of improved future supernovae data on our understanding of the dark energy problem. We carefully examine the relative utility of different fitting functions that can be...
Opportunities for future supernova studies of cosmic acceleration (2000)
Weller, Jochen, Albrecht, Andreas
We investigate the potential of a future supernova dataset, as might be obtained by the proposed SNAP satellite, to discriminate among different ``dark energy'' theories that describe an accelerating...
Bubbles from dark energy ? (2000)
In a model recently proposed by Albrecht and Skordis it was suggested that the observed accelerated expansion of the universe could be caused by a scalar field which is trapped in a local minimum of...
Observational consequences of modern cosmological theories. (2000)
Thesis (Ph. D.)--University of London, 2000.
Inhomogeneous reionization and the polarization of the cosmic microwave background (1999)
In a universe with inhomogeneous reionization, the ionized patches create a second order signal in the cosmic microwave background polarization anisotropy. This signal originates in the coupling of...
Battye, Richard A., Magueijo, Joao, Weller, Jochen
Quantum fluctuations created during inflation can account for the observed matter distribution in the linear regime if the universe has two components of dark matter, one which is cold and...
Reionization by active sources and its effects on the cosmic microwave background (1998)
Weller, Jochen, Battye, Richard A., Albrecht, Andreas
We investigate the possible effects of reionization by active sources on the cosmic microwave background. We concentrate on the sources themselves as the origin of reionization, rather than early...