Nonparametric reconstruction of the dark energy equation of state from diverse data sets
- Department of Applied Mathematics and Statistics, University of California, Santa Cruz, California 95064 (United States)
- ISR-1, MS D466, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
- T-2, MS B285, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
- CCS-6, MS F600, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
The cause of the accelerated expansion of the Universe poses one of the most fundamental questions in physics today. In the absence of a compelling theory to explain the observations, a first task is to develop a robust phenomenological approach: If the acceleration is driven by some form of dark energy, then the phenomenology is determined by the form of the dark energy equation of state w(z) as a function of redshift. A major aim of ongoing and upcoming cosmological surveys is to measure w and its evolution at high accuracy. Since w(z) is not directly accessible to measurement, powerful reconstruction methods are needed to extract it reliably from observations. We have recently introduced a new reconstruction method for w(z) based on Gaussian process modeling. This method can capture nontrivial w(z) dependences and, most importantly, it yields controlled and unbiased error estimates. In this paper we extend the method to include a diverse set of measurements: baryon acoustic oscillations, cosmic microwave background measurements, and supernova data. We analyze currently available data sets and present the resulting constraints on w(z), finding that current observations are in very good agreement with a cosmological constant. In addition, we explore how well our method captures nontrivial behavior of w(z) by analyzing simulated data assuming high-quality observations from future surveys. We find that the baryon acoustic oscillation measurements by themselves already lead to remarkably good reconstruction results and that the combination of different high-quality probes allows us to reconstruct w(z) very reliably with small error bounds.
- OSTI ID:
- 21607860
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 84, Issue 8; Other Information: DOI: 10.1103/PhysRevD.84.083501; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
Similar Records
Nonparametric reconstruction of the dark energy equation of state
Planck 2018 results. VI. Cosmological parameters
Related Subjects
ACCELERATION
BARYONS
COSMOLOGICAL CONSTANT
EQUATIONS OF STATE
EXPANSION
GAUSSIAN PROCESSES
NONLUMINOUS MATTER
OSCILLATIONS
RED SHIFT
RELICT RADIATION
SIMULATION
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
HADRONS
MATTER
MICROWAVE RADIATION
RADIATIONS