A model-independent null test on the cosmological constant

TY - JOUR

T1 - A model-independent null test on the cosmological constant

AU - Nesseris, Savvas

AU - Shafieloo, Arman

PY - 2010/11/1

Y1 - 2010/11/1

N2 - We use the Om statistic and the genetic algorithms (GAs) in order to derive a null test on the spatially flat cosmological constant model Lambda cold dark matter (ΛCDM). This is done in two steps: first, we apply the GAs to the Constitution SNIa data in order to acquire a model-independent reconstruction of the expansion history of the Universe H(z) and secondly, we use the reconstructed H(z) in conjunction with the Om statistic, which is constant only for the ΛCDM model, to derive our constraints. We find that while ΛCDM is consistent with the data at the 2σ level, some deviations from ΛCDM model at low redshifts can be accommodated.

AB - We use the Om statistic and the genetic algorithms (GAs) in order to derive a null test on the spatially flat cosmological constant model Lambda cold dark matter (ΛCDM). This is done in two steps: first, we apply the GAs to the Constitution SNIa data in order to acquire a model-independent reconstruction of the expansion history of the Universe H(z) and secondly, we use the reconstructed H(z) in conjunction with the Om statistic, which is constant only for the ΛCDM model, to derive our constraints. We find that while ΛCDM is consistent with the data at the 2σ level, some deviations from ΛCDM model at low redshifts can be accommodated.

U2 - 10.1111/j.1365-2966.2010.17254.x

DO - 10.1111/j.1365-2966.2010.17254.x

M3 - Journal article

SN - 0035-8711

VL - 408

SP - 1879

EP - 1885

JO - Royal Astronomical Society. Monthly Notices

JF - Royal Astronomical Society. Monthly Notices

IS - 3

ER -