Testing Standard Cosmology with Large Scale Structure (2009)
Stril, Arthur, Cahn, Robert N., Linder, Eric V.
The galaxy power spectrum contains information on the growth of structure, the growth rate through redshift space distortions, and the cosmic expansion through baryon acoustic oscillation features....
How many dark energy parameters? (2009)
For exploring the physics behind the accelerating universe a crucial question is how much we can learn about the dynamics through next generation cosmological experiments. For example, in defining...
Dark Energy Properties in DBI Theory (2009)
Ahn, Changrim, Kim, Chanju, Linder, Eric V.
The Dirac-Born-Infeld (DBI) action from string theory provides several new classes of dark energy behavior beyond quintessence due to its relativistic kinematics. We constrain parameters of natural...
Cortês, Marina, Linder, Eric V.
Dark energy dynamics in the recent universe is influenced by its evolution through the long, matter dominated expansion history. A particular dynamical property, the flow variable, remains constant...
Cosmic Growth History and Expansion History (2009)
The cosmic expansion history tests the dynamics of the global evolution of the universe and its energy density contents, while the cosmic growth history tests the evolution of the inhomogeneous part...
Theory Challenges of the Accelerating Universe (2009)
The accelerating expansion of the universe presents an exciting, fundamental challenge to the standard models of particle physics and cosmology. I highlight some of the outstanding challenges in both...
Cosmology with X-ray Cluster Baryons (2009)
X-ray cluster measurements interpreted with a universal baryon/gas mass fraction can theoretically serve as a cosmological distance probe. We examine issues of cosmological sensitivity for current...
Biased Cosmology: Pivots, Parameters, and Figures of Merit (2009)
In the quest for precision cosmology, one must ensure that the cosmology is accurate as well. We discuss figures of merit for determining from observations whether the dark energy is a cosmological...
Dark Energy in the Dark Ages (2009)
Non-negligible dark energy density at high redshifts would indicate dark energy physics distinct from a cosmological constant or "reasonable'" canonical scalar fields. Such dark...
Generating and Analyzing Constrained Dark Energy Equations of State and Systematics Functions (2009)
Samsing, Johan, Linder, Eric V.
Some functions entering cosmological analysis, such as the dark energy equation of state or systematic uncertainties, are unknown functions of redshift. To include them without assuming a particular...
We investigate a f(R) modification of gravity exponential in the Ricci scalar R to explain cosmic acceleration. The steepness of the dependence provides extra freedom to satisfy solar system and...
Cosmological Constant Behavior in DBI Theory (2009)
Ahn, Changrim, Kim, Chanju, Linder, Eric V.
Cosmological constant behavior can be realized as solutions of the Dirac-Born-Infeld (DBI) action within Type IIB string theory and the AdS/CFT correspondence. We derive a family of attractor...
CMB Lensing Constraints on Neutrinos and Dark Energy (2009)
De Putter, Roland, Zahn, Oliver, Linder, Eric V.
Signatures of lensing of the cosmic microwave background radiation by gravitational potentials along the line of sight carry with them information on the matter distribution, neutrino masses, and...
Extending the Gravitational Growth Framework (2009)
The gravitational growth index formalism provides a model independent way to look for deviations from general relativity by testing dark energy physics distinct from its effects on the cosmic...
Being PC: Principal Components and Dark Energy (2008)
De Putter, Roland, Linder, Eric V.
Principal component analysis is considered as an addition to the well-tested parametrization w(a)=w_0+w_a(1-a) for the dark energy equation of state. This brief note cautions against some unjustified...
Like vs. Like: Strategy and Improvements in Supernova Cosmology Systematics (2008)
Control of systematic uncertainties in the use of Type Ia supernovae as standardized distance indicators can be achieved through contrasting subsets of observationally-characterized, like supernovae....
Aetherizing Lambda: Barotropic Fluids as Dark Energy (2008)
Linder, Eric V., Scherrer, Robert J.
We examine the class of barotropic fluid models of dark energy, in which the pressure is an explicit function of the density, p = f(\rho). Through general physical considerations we constrain the...
A Cosmic Vision Beyond Einstein (2008)
The acceleration of the cosmic expansion is a fundamental challenge to standard models of particle physics and cosmology. The new physics of dark energy may lie in the nature of gravity, the quantum...
Halo Mass Functions in Early Dark Energy Cosmologies (2008)
Francis, Matthew J., Lewis, Geraint F., Linder, Eric V.
We examine the linear density contrast at collapse time, $\delta_c$ for large-scale structure in dynamical dark energy cosmologies, including models with early dark energy. Contrary to previous...
Can Early Dark Energy be Detected in Non-Linear Structure? (2008)
Francis, Matthew J., Lewis, Geraint F., Linder, Eric V.
We present the first study of early dark energy cosmologies using N-body simulations to investigate the formation of non-linear structure. In contrast to expectations from semi-analytic approaches,...
Calibrating Dark Energy (2008)
De Putter, Roland, Linder, Eric V.
Exploring the diversity of dark energy dynamics, we discover a calibration relation, a uniform stretching of the amplitude of the equation of state time variation with scale factor. This defines...
Field Flows of Dark Energy (2008)
Cahn, Robert N., De Putter, Roland, Linder, Eric V.
Scalar field dark energy evolving from a long radiation- or matter-dominated epoch has characteristic dynamics. While slow-roll approximations are invalid, a well defined field expansion captures the...
Shifting the Universe: Early Dark Energy and Standard Rulers (2008)
Linder, Eric V., Robbers, Georg
The presence of dark energy at high redshift influences both the cosmic sound horizon and the distance to last scattering of the cosmic microwave background. We demonstrate that through the...
Mapping the Cosmological Expansion (2008)
The ability to map the cosmological expansion has developed enormously, spurred by the turning point one decade ago of the discovery of cosmic acceleration. The standard model of cosmology has...
Improved cosmological constraints from new, old, and combined supernova data sets (2008)
Kowalski, M., Rubin, D., Aldering, G., Agostinho, R. J., Amadon, A., Amanullah, R., ...
We present a new compilation of Type Ia supernovae (SNe Ia), a new data set of low-redshift nearby-Hubble-flow SNe, and new analysis procedures to work with these heterogeneous compilations. This...
Improved cosmological constraints from new, old, and combined supernova data sets (2008)
Kowalski, M., Rubin, D., Aldering, G., Agostinho, R. J., Amadon, A., Amanullah, R., ...
We present a new compilation of Type Ia supernovae (SNe Ia), a new data set of low-redshift nearby-Hubble-flow SNe, and new analysis procedures to work with these heterogeneous compilations. This...
Gravitational Wave Sirens as a Triple Probe of Dark Energy (2007)
Gravitational wave standard sirens have been considered as precision distance indicators to high redshift; however, at high redshift standard sirens or standard candles such as supernovae suffer from...
To Bin or Not To Bin: Decorrelating the Cosmic Equation of State (2007)
De Putter, Roland, Linder, Eric V.
The physics behind the acceleration of the cosmic expansion can be elucidated through comparison of the predictions of dark energy equations of state to observational data. In seeking to optimize...
Redshift Distortions as a Probe of Gravity (2007)
Redshift distortion measurements from galaxy surveys include sensitivity to the gravitational growth index distinguishing other theories from Einstein gravity. This gravitational sensitivity is...
We demonstrate that cosmic microwave background observations consistent with a cosmological constant universe predict in a well-defined sense that lower redshift measures will nearly automatically...
Resource Letter: Dark Energy and the Accelerating Universe (2007)
This Resource Letter provides a guide to the literature on dark energy and the accelerating universe. It is intended to be of use to researchers, teachers, and students at several levels. Journal...
Kinetic k-essence and Quintessence (2007)
De Putter, Roland, Linder, Eric V.
Dark energy models with non-canonical kinetic energy terms, k-essence, can have dynamical and sound speed properties distinct from canonical scalar fields, quintessence. Concentrating on purely...
The Dynamics of Quintessence, The Quintessence of Dynamics (2007)
Quintessence theories for cosmic acceleration imbue dark energy with a non-trivial dynamics that offers hope in distinguishing the physical origin of the component. We review quintessence models with...
Power Spectra to 1% Accuracy between Dynamical Dark Energy Cosmologies (2007)
Francis, Matthew J., Lewis, Geraint F., Linder, Eric V.
For dynamical dark energy cosmologies we carry out a series of N-body gravitational simulations, achieving percent level accuracy in the relative mass power spectra at any redshift. Such accuracy in...
Tainted Evidence: Cosmological Model Selection vs. Fitting (2007)
Linder, Eric V., Miquel, Ramon
Interpretation of cosmological data to determine the number and values of parameters describing the universe must not rely solely on statistics but involve physical insight. When statistical...
Universe's Skeleton Sketched (2007)
The deepest and clearest maps yet of the Universe's skeleton of dark matter structure present a picture broadly in concord with favoured models - although puzzling discrepancies remain.
Parameterized Beyond-Einstein Growth (2007)
Linder, Eric V., Cahn, Robert N.
A single parameter, the gravitational growth index \gamma, succeeds in characterizing the growth of density perturbations in the linear regime separately from the effects of the cosmic expansion. The...
Dark Energy with a Fine-toothed Comb (2006)
The cosmological constant and many other possible origins for acceleration of the cosmic expansion possess variations in the dark energy properties slow on the Hubble time scale. Given that models...
Theory Challenges of the Accelerating Universe (2006)
The accelerating expansion of the universe presents an exciting, fundamental challenge to the standard models of particle physics and cosmology. I highlight some of the outstanding challenges in both...
Importance of Supernovae at z (2006)
Supernova experiments to characterize dark energy require a well designed low redshift program; we consider this for both ongoing/near term (e.g. Supernova Legacy Survey) and comprehensive future...
Separating Dark Physics from Physical Darkness: Minimalist Modified Gravity vs. Dark Energy (2006)
Huterer, Dragan, Linder, Eric V.
The acceleration of the cosmic expansion may be due to a new component of physical energy density or a modification of physics itself. Mapping the expansion of cosmic scales and the growth of large...
Snapping Supernovae at z>1.7 (2006)
Aldering, Greg, Kim, Alex G., Kowalski, Marek, Linder, Eric V., Perlmutter, Saul
We examine the utility of very high redshift Type Ia supernovae for cosmology and systematic uncertainty control. Next generation space surveys such as the Supernova/Acceleration Probe (SNAP) will...
Cosmology with X-ray Cluster Baryons (2006)
X-ray cluster measurements interpreted with a universal baryon/gas mass fraction can theoretically serve as a cosmological distance probe. We examine issues of cosmological sensitivity for current...
Biased Cosmology: Pivots, Parameters, and Figures of Merit (2006)
In the quest for precision cosmology, one must ensure that the cosmology is accurate as well. We discuss figures of merit for determining from observations whether the dark energy is a cosmological...
Dark Energy in the Dark Ages (2006)
Non-negligible dark energy density at high redshifts would indicate dark energy physics distinct from a cosmological constant or ``reasonable'' canonical scalar fields. Such dark energy can be...
The Paths of Quintessence (2006)
The structure of the dark energy equation of state phase plane holds important information on the nature of the physics. We explain the bounds of the freezing and thawing models of scalar field dark...
On Oscillating Dark Energy (2005)
Distance-redshift data can impose strong constraints on dark energy models even when the equation of state is oscillatory. Despite the double integral dependence of the distance on the equation of...
Seeing Darkness: the New Cosmology (2005)
We present some useful ways to visualize the nature of dark energy and the effects of the accelerating expansion on cosmological quantities. Expansion probes such as Type Ia supernovae distances and...
The Influence of Evolving Dark Energy on Cosmology (2005)
Barnes, Luke, Francis, Matthew J., Lewis, Geraint F., Linder, Eric V.
Observational evidence indicating that the expansion of the universe is accelerating has surprised cosmologists in recent years. Cosmological models have sought to explain this acceleration by...
Going Nonlinear with Dark Energy Cosmologies (2005)
Linder, Eric V., White, Martin
We propose an efficient method for generating high accuracy (~1%) nonlinear power spectra for grids of dark energy cosmologies. Our prescription for matching matter growth automatically matches the...
Curved Space or Curved Vacuum? (2005)
While the simple picture of a spatially flat, matter plus cosmological constant universe fits current observation of the accelerated expansion, strong consideration has also been given to models with...
The Ups and Downs of Baryon Oscillations (2005)
Baryon acoustic oscillations, measured through the patterned distribution of galaxies or other baryon tracing objects on very large (100 Mpc) scales, offer a possible geometric probe of cosmological...
Cosmic Growth History and Expansion History (2005)
The cosmic expansion history tests the dynamics of the global evolution of the universe and its energy density contents, while the cosmic growth history tests the evolution of the inhomogeneous part...
The Limits of Quintessence (2005)
Caldwell, R. R., Linder, Eric V.
We present evidence that the simplest particle-physics scalar-field models of dynamical dark energy can be separated into distinct behaviors based on the acceleration or deceleration of the field as...
How many dark energy parameters? (2005)
Linder, Eric V., Huterer, Dragan
For exploring the physics behind the accelerating universe a crucial question is how much we can learn about the dynamics through next generation cosmological experiments. For example, in defining...
Dealing with Dark Energy (2005)
Discoveries in the last few years have revolutionized our knowledge of the universe and our ideas of its ultimate fate. Measurements of the expansion of the universe show that it is not slowing down...
Holz, Daniel E., Linder, Eric V.
Observation of the expansion history of the Universe allows exploration of the physical properties and energy density of the Universe's various constituents. Standardizable candles such as Type Ia...
Dark Entropy: Holographic Cosmic Acceleration (2004)
In cosmic holography, the fundamental quantity is the degrees of freedom on a horizon surface rather than the material contents within the volume. That is, the horizon area and hence cosmological...
Is Dark Energy Dynamical? Prospects for an Answer (2004)
Linder, Eric V., Miquel, Ramon
Recent data advances offer the exciting prospect of a first look at whether dark energy has a dynamical equation of state or not. While formally theories exist with a constant equation of state, they...
Reconstructing and Deconstructing Dark Energy (2004)
The acceleration of the expansion of the universe, ascribed to a dark energy, is one of the most intriguing discoveries in science. In addition to precise, systematics controlled data, clear, robust...
Observing Dark Energy with SNAP (2004)
Linder, Eric V., Collaboration, For The SNAP
The nature of dark energy is of such fundamental importance -- yet such a mystery -- that a dedicated dark energy experiment should be as comprehensive and powerfully incisive as possible. The...
Light Thoughts on Dark Energy (2004)
The physical process leading to the acceleration of the expansion of the universe is unknown. It may involve new high energy physics or extensions to gravitation. Calling this generically dark...
Probing Gravitation, Dark Energy, and Acceleration (2004)
The acceleration of the expansion of the universe arises from unknown physical processes involving either new fields in high energy physics or modifications of gravitation theory. It is crucial for...
Strong Gravitational Lensing and Dark Energy Complementarity (2004)
In the search for the nature of dark energy most cosmological probes measure simple functions of the expansion rate. While powerful, these all involve roughly the same dependence on the dark energy...
Testing the Cosmological Constant as a Candidate for Dark Energy (2003)
Kratochvil, Jan, Linde, Andrei, Linder, Eric V., Shmakova, Marina
It may be difficult to single out the best model of dark energy on the basis of the existing and planned cosmological observations, because many different models can lead to similar observational...
Mapping the Dark Energy Equation of State (2003)
The acceleration of the expansion of the universe has deep implications for structure formation, the composition of the universe, and its fate. Roughly 70% of the energy density is in a dark energy,...
Observational Bounds on Cosmic Doomsday (2003)
Kallosh, Renata, Kratochvil, Jan, Linde, Andrei, Linder, Eric V., Shmakova, Marina
Recently it was found, in a broad class of models, that the dark energy density may change its sign during the evolution of the universe. This may lead to a global collapse of the universe within the...
Cosmic Structure Growth and Dark Energy (2003)
Linder, Eric V., Jenkins, Adrian
Dark energy has a dramatic effect on the dynamics of the universe, causing the recently discovered acceleration of the expansion. The dynamics are also central to the behavior of the growth of large...
Effects of Systematic Uncertainties on the Supernova Determination of Cosmological Parameters (2003)
Kim, Alex G., Linder, Eric V., Miquel, Ramon, Mostek, Nick
Mapping the recent expansion history of the universe offers the best hope for uncovering the characteristics of the dark energy believed to be responsible for the acceleration of the expansion. In...
Baryon Oscillations as a Cosmological Probe (2003)
Mapping the expansion of the universe gives clues to the underlying physics causing the recently discovered acceleration of the expansion, and enables discrimination among cosmological models. We...
Dark Energy, Expansion History of the Universe, and SNAP (2003)
This talk presents a pedagogical discussion of how precision distance-redshift observations can map out the recent expansion history of the universe, including the present acceleration and the...
Cosmic Shear with Next Generation Redshift Surveys as a Cosmological Probe (2002)
The expansion of the universe causes spacetime curvature, distinguishing between distances measured along and transverse to the line of sight. The ratio of these distances, e.g. the cosmic shear...
Probing Dark Energy with SNAP (2002)
The distance-redshift relation observed for supernovae has led to the discovery that the expansion of the universe is accelerating. A next generation experiment, the Supernova/Acceleration Probe...
Exploring the Expansion History of the Universe (2002)
Exploring the recent expansion history of the universe promises insights into the cosmological model, the nature of dark energy, and potentially clues to high energy physics theories and gravitation....
Importance of Supernovae at z>1.5 to Probe Dark Energy (2002)
Linder, Eric V., Huterer, Dragan
The accelerating expansion of the universe suggests that an unknown component with strongly negative pressure, called dark energy, currently dominates the dynamics of the universe. Such a component...
Frieman, Joshua A., Huterer, Dragan, Linder, Eric V., Turner, Michael S.
A primary goal for cosmology and particle physics over the coming decade will be to unravel the nature of the dark energy that drives the accelerated expansion of the Universe. In particular,...
Understanding the Optimal Redshift Range for the Supernovae Hubble Diagram (2001)
The supernovae Hubble diagram traces the expansion history of the universe, including the influence of dark energy. Its use to probe the cosmological model can fruitfully be guided by heuristic study...
Averaging Inhomogeneous Universes: Volume, Angle, Line of Sight (1998)
Cosmologies that match in a volume averaged sense need not generally have the same light propagation behaviors. In particular a universe with inhomogeneity may not demonstrate the...
Acoustic Peak Spacing, Cosmological Density, and Equation of State (1997)
The spacing of the acoustic peaks in the cosmic microwave background radiation anisotropy multipole spectrum has been claimed to provide the value of the total cosmological density overtly, ``written...
Transition from Clumpy to Smooth Angular Diameter Distances (1997)
Distance relations in a locally inhomogeneous universe are expected to behave like the Dyer-Roeder solution on small angular scales and the Friedmann-Robertson-Walker solution on large angular...
Post-Newtonian Sachs-Wolfe Effect (1997)
Deviations from the Friedmann-Robertson-Walker (FRW) cosmological model in the form of density inhomogeneities induce observational effects on the light propagating through these fluctuations. Using...
Cosmological parametrization of gamma ray burst models (1996)
Using three parametrizations of the gamma ray burst count data comparison is made to cosmological source models. While simple models can fit and faint end slope constraints, the addition of a...
Correlated gravitational lensing of the CMB (1996)
Cosmological inhomogeneities gravitationally deflect radiation propagating from distant sources, transforming the spatial and angular correlation functions of intrinsic source properties. For a...
A Green Function for Metric Perturbations due to Cosmological Density Fluctuations (1993)
Jacobs, Mark W, Linder, Eric V, Wagoner, Robert V
We study scalar perturbations to a Robertson-Walker cosmological metric in terms of a pseudo-Newtonian potential, which emerges naturally from the solution of the field equations. This potential is...