de Sitter equilibrium as a fundamental framework for cosmology (2009)
Cosmology might turn out to be the study of fluctuations around a "de Sitter equilibrium" state. In this article I review the basic ideas and the attractive features of this framework, and respond to...
Effects of Inhomogeneity on the Causal Entropic prediction of Lambda (2009)
Phillips, Daniel, Albrecht, Andreas
The Causal Entropic Principle aims to predict the unexpectedly small value of the cosmological constant Lambda using a weighting by entropy increase on causal diamonds. The original work assumed a...
The Case for Deep, Wide-Field Cosmology (2009)
Scranton, Ryan, Albrecht, Andreas, Caldwell, Robert, Cooray, Asantha, Dore, Olivier, Habib, Salman, ...
Much of the science case for the next generation of deep, wide-field optical/infrared surveys has been driven by the further study of dark energy. This is a laudable goal (and the subject of a...
Exploring Dark Energy with Next-Generation Photometric Redshift Surveys (2009)
Zhan, Hu, Albrecht, Andreas, Cooray, Asantha, Habib, Salman, Heavens, Alan, Heitmann, Katrin, ...
The coming decade will be an exciting period for dark energy research, during which astronomers will address the question of what drives the accelerated cosmic expansion as first revealed by type Ia...
Curvature Constraints from the Causal Entropic Principle (2009)
Bozek, Brandon, Albrecht, Andreas, Phillips, Daniel
Current cosmological observations indicate a preference for a cosmological constant that is drastically smaller than what can be explained by conventional particle physics. The Causal Entropic...
Findings of the Joint Dark Energy Mission Figure of Merit Science Working Group (2009)
Albrecht, Andreas, Amendola, Luca, Bernstein, Gary, Clowe, Douglas, Eisenstein, Daniel, Guzzo, Luigi, ...
These are the findings of the Joint Dark Energy Mission (JDEM) Figure of Merit (FoM) Science Working Group (SWG), the FoMSWG. JDEM is a space mission planned by NASA and the DOE for launch in the...
REPORT OF THE DARK ENERGY TASK FORCE (2008)
Andreas Albrecht, Wendy L. Freedman, Carnegie Observatories, John Huth, John C. Mather, Goddard Space
Dark energy appears to be the dominant component of the physical Universe, yet there is no persuasive theoretical explanation for its existence or magnitude. The acceleration of the Universe is,...
Exploring Parameter Constraints on Quintessential Dark Energy: the Inverse Power Law Model (2008)
Yashar, Mark, Bozek, Brandon, Abrahamse, Augusta, Albrecht, Andreas, Barnard, Michael
We report on the results of a Markov Chain Monte Carlo (MCMC) analysis of an inverse power law (IPL) quintessence model using the Dark Energy Task Force (DETF) simulated data sets as a representation...
The clock ambiguity: Implications and new developments (2008)
Albrecht, Andreas, Iglesias, Alberto
We consider the ambiguity associated with the choice of clock in time reparameterization invariant theories. This arbitrariness undermines the goal of prescribing a fixed set of physical laws, since...
Barnard, Michael, Abrahamse, Augusta, Albrecht, Andreas, Bozek, Brandon, Yashar, Mark
We evaluate the ability of future data sets to discriminate among different quintessence dark energy models. This approach gives an alternative measure for assessing the impact of future experiments,...
Exploring Parameter Constraints on Quintessential Dark Energy: the Albrecht-Skordis model (2007)
Barnard, Michael, Abrahamse, Augusta, Albrecht, Andreas, Bozek, Brandon, Yashar, Mark
We consider the effect of future dark energy experiments on ``Albrecht-Skordis'' (AS) models of scalar field dark energy using the Monte-Carlo Markov chain method. We deal with the issues of...
Abrahamse, Augusta, Albrecht, Andreas, Barnard, Michael, Bozek, Brandon
We analyze the constraining power of future dark energy experiments for Pseudo-Nambu Goldstone Boson (PNGB) quintessence. Following the Dark Energy Task Force methodology, we forecast data for three...
Exploring Parameter Constraints on Quintessential Dark Energy: The Exponential Model (2007)
Bozek, Brandon, Abrahamse, Augusta, Albrecht, Andreas, Barnard, Michael
We present an analysis of a scalar field model of dark energy with an exponential potential using the Dark Energy Task Force (DETF) simulated data models. Using Markov Chain Monte Carlo sampling...
The case for an aggressive program of dark energy probes (2007)
The observed cosmic acceleration presents the physics and cosmology communities with amazing opportunities to make exciting, probably even radical advances in these fields. This topic is highly data...
The clock ambiguity and the emergence of physical laws (2007)
Albrecht, Andreas, Iglesias, Alberto
The process of identifying a time variable in time reparameterization invariant theories results in great ambiguities about the actual laws of physics described by a given theory. A theory set up to...
Report of the Dark Energy Task Force (2006)
Albrecht, Andreas, Bernstein, Gary, Cahn, Robert, Freedman, Wendy L., Hewitt, Jacqueline, Hu, Wayne, ...
Dark energy appears to be the dominant component of the physical Universe, yet there is no persuasive theoretical explanation for its existence or magnitude. The acceleration of the Universe is,...
Evaluating Dark Energy Probes using Multi-Dimensional Dark Energy Parameters (2006)
Albrecht, Andreas, Bernstein, Gary
We investigate the value of future dark energy experiments by modeling their ability to constrain the dark energy equation of state. Similar work was recently reported by the Dark Energy Task Force...
Martin, Damien, Albrecht, Andreas
We consider two different methods of parameterizing the dark energy equation of state in order to assess possible ``figures of merit'' for evaluating dark energy experiments. The two models are $w(a)...
On Open Inflation, the string theory landscape and the low CMB quadrupole (2004)
Barnard, Michael, Albrecht, Andreas
Cosmologists have embraced a particular ad hoc formula for the primordial power spectrum from inflation for universes with $\Omega_0 < 1$. However, the so-called ``Open Inflation'' models, which are...
Can the universe afford inflation? (2004)
Albrecht, Andreas, Sorbo, Lorenzo
Cosmic inflation is envisioned as the ``most likely'' start for the observed universe. To give substance to this claim, a framework is needed in which inflation can compete with other scenarios and...
Next-generation test of cosmic inflation (2003)
Gold, Benjamin, Albrecht, Andreas
The increasing precision of cosmological datasets is opening up new opportunities to test predictions from cosmic inflation. Here we study the impact of high precision constraints on the primordial...
Holographic Limitations of the Effective Field Theory of Inflation (2002)
Albrecht, Andreas, Kaloper, Nemanja, Song, Yong-Seon
Holographic considerations may provide a glimpse of quantum gravity beyond what is currently accessible by other means. Here we apply holography to inflationary cosmology. We argue that the...
Cosmic Inflation and the Arrow of Time (2002)
Cosmic inflation claims to make the initial conditions of the standard big bang "generic". But Boltzmann taught us that the thermodynamic arrow of time arises from very non-generic ("low entropy")...
Albrecht, Andreas, Frieman, Joshua A., Trodden, Mark
This is the report of the {\em Working Group on Early Universe Cosmology and Tests of Fundamental Physics}, group P4.8 of the of the Snowmass 2001 conference. Here we summarize the impressive array...
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...
Planck-scale quintessence and the physics of structure formation (2000)
Skordis, Constantinos, Albrecht, Andreas
In a recent paper we considered the possibility of a scalar field providing an explanation for the cosmic acceleration. Our model had the interesting properties of attractor-like behavior and having...
Defect models of cosmic structure in light of the new CMB data (2000)
Defect models of cosmic structure formation have faced a number of difficult challenges over recent years. Yet interestingly, new CMB data does not show strong evidence for secondary oscillations in...
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...
I review the current status of the theory of Cosmic Inflation. My discussion covers the motivation and implementation of the idea, as well as an analysis of recent successes and open questions. There...
Phenomenology of a realistic accelerating universe using only Planck-scale physics (1999)
Albrecht, Andreas, Skordis, Constantinos
Modern data is showing increasing evidence that the Universe is accelerating. So far, all attempts to account for the acceleration have required some fundamental dimensionless quantities to be...
Can inflationary models of cosmic perturbations evade the secondary oscillation test? (1999)
Lewin, Alex, Albrecht, Andreas
We consider the consequences of an observed Cosmic Microwave Background (CMB) temperature anisotropy spectrum containing no secondary oscillations. While such a spectrum is generally considered to be...
Cosmology with a time-varying speed of light (1999)
Cosmic inflation is the only known mechanism with the potential to explain the very special initial conditions which are required at the early stages of the evolution of our universe. This article...
A time varying speed of light as a solution to cosmological puzzles (1998)
Albrecht, Andreas, Magueijo, Joao
We consider the cosmological implications of light travelling faster in the early Universe. We propose a prescription for deriving corrections to the cosmological evolution equations while the speed...
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...
A new statistic for picking out Non-Gaussianity in the CMB (1998)
Lewin, Alex, Albrecht, Andreas, Magueijo, Joao
In this paper we propose a new statistic capable of detecting non-Gaussianity in the CMB. The statistic is defined in Fourier space, and therefore naturally separates angular scales. It consists of...
What is the future of causal models of cosmic structure formation? (1998)
Recent research has severely constrained the standard ``defect'' models of cosmic structure formation. Here I discuss the nature of the problems with defect models, and place this discussion in the...
Zugl.: Giessen, Universiẗat, Diss., 1997.
The case against scaling defect models of cosmic structure formation (1997)
Albrecht, Andreas, Battye, Richard A., Robinson, James
We calculate predictions from defect models of structure formation for both the matter and Cosmic Microwave Background (CMB) over all observable scales. Our results point to a serious problem...
Coherence and Sakharov Oscillations in the Microwave Sky (1996)
I discuss the origin of the ``Sakharov oscillations'' (or ``secondary Doppler peaks'') in standard angular power spectra of the Cosmic Microwave Background anisotropies calculated for inflationary...
How to falsify scenarios with primordial fluctuations from inflation (1996)
I argue that the proposition that primordial perturbations were produced by inflation is most definitely falsifyable. Far from ``predicting anything you want'', the Gaussianity and passivity of...
The structure of Doppler peaks induced by active perturbations (1996)
Magueijo, Joao, Albrecht, Andreas, Ferreira, Pedro, Coulson, David
We investigate how the qualitative structure of Doppler peaks in the angular power spectrum of the cosmic microwave anisotropy is affected by basic assumptions going into theories of structure...
Satellite design parameters for detecting coherence in the microwave sky (1996)
Albrecht, Andreas, Wandelt, Benjamin D.
Recently it has been realized that observations of fluctuations in the cosmic microwave background (CMB) can reveal very interesting information about the degree of coherence exhibited by the...
Doppler peaks from active perturbations (1995)
Magueijo, Joao, Albrecht, Andreas, Coulson, David, Ferreira, Pedro
We examine how the qualitative structure of the Doppler peaks in the angular power spectrum of the cosmic microwave anisotropy depends on the fundamental nature of the perturbations which produced...
A Statistic for identifying cosmic string wakes and other sheet-like structure (1995)
Robinson, James, Albrecht, Andreas
We describe an implementation of the structure functions of Babul \& Starkman, in order to quantify the ``sheet-like'' nature of a distribution of matter. We test this statistic on a toy model...
Causality, randomness, and the microwave background (1995)
Albrecht, Andreas, Coulson, David, Ferreira, Pedro, Magueijo, Joao
Fluctuations in the cosmic microwave background (CMB) temperature are being studied with ever increasing precision. Two competing types of theories might describe the origins of these fluctuations:...
The Theory of Everything vs the Theory of Anything (1994)
To what extent can our limited set of observations be used to pin down the specifics of a ``Theory of Everything''? In the limit where the links are arbitrarily tenuous, a ``Theory of Everything''...
Locating Overlap Information in Quantum Systems (1994)
When discussing the black hole information problem the term ``information flow'' is frequently used in a rather loose fashion. In this article I attempt to make this notion more concrete. I consider...
Some Remarks on Quantum Coherence (1994)
There are many striking phenomena which are attributed to ``quantum coherence''. It is natural to wonder if there are new quantum coherence effects waiting to be discovered which could lead to...
Following a "Collapsing" Wavefunction (1993)
I study the quantum mechanics of a spin interacting with an ``apparatus''. Although the evolution of the whole system is unitary, the spin evolution is not. The system is chosen so that the spin...
Inflation and squeezed quantum states (1993)
Albrecht, Andreas, Ferreira, Pedro, Joyce, Michael, Prokopec, Tomislav
The inflationary cosmology is analyzed from the point of view of squeezed quantum states. As noted by Grishchuk and Sidorov, the amplification of quantum fluctuations into macroscopic perturbations...
ORACLE$*$CASE in CERN's accelerator sector (1992)
Albrecht, Andreas, Cabas-Alonso, A, Chevrier, F L, Daneels, A, Delamare, C, Ferran, G, ...
CERN's accelerator description using databases (1992)
Albrecht, Andreas, Billen, R, Bordry, Frederick, Marti, Y, Poole, John
CASE in CERN's accelerator sector (1992)
Albrecht, Andreas, Cabas-Alonso, A, Chevrier, F L, Daneels, A, Delamare, C, Ferran, G, ...
Beiträge zur Kompliziertheitstheorie Boolescher Funktionen. (1988)
Berlin, Humboldt-Univ., Diss. B, 1988 (Nicht f.d. Austausch).
Deterministic Simulation of Idealized Parallel Computers on more Realistic Ones (1987)
Alt, Helmut, Hagerup, Torben, Mehlhorn, Kurt, Preparata, Franco P., Albrecht, Andreas, Jung, Hermann, ...
Third party rights under inter-bank contracts : a comparative study / (1985)
Written for the Institute of Comparative Law.
Third party rights under inter-bank contracts : a comparative study / (1985)
Written for the Institute of Comparative Law, McGill University.
New inflation in supersymmetric theories (1983)
Albrecht, Andreas, Dimopoulos, Savas, Fischler, W., Kolb, Edward W., Raby, Stuart, Steinhardt, Paul J.
A new inflationary universe scenario is considered based upon phase transitions in supersymmetric unified models where the Higgs potential is of the Witten-O'Raifeartaigh type.