Is Dark Energy the Only Solution to the Apparent Acceleration of the Present Universe?

Iguchi, Hideo; Nakamura, Takashi; Nakao, Ken–ichi

doi:10.1143/ptp.108.809

Cited by 143 publications

(195 citation statements)

References 15 publications

Supporting

Mentioning

191

Contrasting

Order By: Relevance

“…that the L-T bang-time function t B is constant. With t B being constant, the only singlepatch L-T model that fits observations is one with a giant void (Iguchi et al 2002;Yoo et al 2008). Conceptually there is nothing wrong with a non-simultaneous big bang (even though this is a radical qualitative difference with the FLRW models), but one should exercise caution when referring to (t−t B ) as the actual age of the Universe.…”

Section: The Historical Background Of the Problemmentioning

confidence: 99%

“…Three classes of models have been constructed with the L-T solution: i) models where the observer is located at the centre of a single L-T universe (e.g., Iguchi et al 2002;Alnes et al 2006;Apostolopoulos et al 2006;Bolejko 2008;Garcia-Bellido & Haugbølle 2008a; ii) models where the observer is located off the centre of such a universe (e.g., Schneider & Célérier 1999;Apostolopoulos et al 2006;Alnes & Amarzguioui 2007) 1 ; iii) Swiss-cheese models where the holes are L-T bubbles carved out of a Friedmannian homogeneous background (e.g., Brouzakis et al 2007Brouzakis et al , 2008Biswas & Notari 2008;Marra et al 2007). …”

Section: The Historical Background Of the Problemmentioning

confidence: 99%

See 1 more Smart Citation

A (giant) void is not mandatory to explain away dark energy with a Lemaître-Tolman model

Célérier¹,

Bolejko

Krasiński

2010

A&A

159

View full text Add to dashboard Cite

Context. Lemaître-Tolman (L-T) toy models with a central observer have been used to study the effect of large scale inhomogeneities on the SN Ia dimming. Claims that a giant void is mandatory to explain away dark energy in this framework are currently dominating. Aims. Our aim is to show that L-T models exist that reproduce a few features of the ΛCDM model, but do not contain the giant cosmic void. Methods. We propose to use two sets of data -the angular diameter distance together with the redshift-space mass-density and the angular diameter distance together with the expansion rate -both defined on the past null cone as functions of the redshift. We assume that these functions are of the same form as in the ΛCDM model. Using the Mustapha-Hellaby-Ellis algorithm, we numerically transform these initial data into the usual two L-T arbitrary functions and solve the evolution equation to calculate the mass distribution in spacetime. Results. For both models, we find that the current density profile does not exhibit a giant void, but rather a giant hump. However, this hump is not directly observable, since it is in a spacelike relation to a present observer.

show abstract

Section: The Historical Background Of the Problemmentioning

confidence: 99%

Section: The Historical Background Of the Problemmentioning

confidence: 99%

A (giant) void is not mandatory to explain away dark energy with a Lemaître-Tolman model

Célérier¹,

Bolejko

Krasiński

2010

A&A

159

View full text Add to dashboard Cite

show abstract

“…The LTB model has been used for the supernova data fitting several times before [23,24,[26][27][28][29][30]. However, there is a crucial physical difference between these models and ours.…”

Section: Spherically Symmetric Inhomogeneous Ltb Modelmentioning

confidence: 99%

The effect of inhomogeneous expansion on the supernova observations

Enqvist¹,

Mattsson²

2007

J. Cosmol. Astropart. Phys.

156

204

View full text Add to dashboard Cite

Abstract:We consider an inhomogeneous but spherically symmetric LemaitreTolman-Bondi model to demonstrate that spatial variations of the expansion rate can have a significant effect on the cosmological supernova observations. A model with no dark energy but a local Hubble parameter about 15 % larger than its global value fits the supernova data better than the homogeneous model with the cosmological constant. The goodness of the fit is not sensitive to inhomogeneities in the present-day matter density, and our best fit model has Ω M (r) ∼ 0.3, in agreement with galaxy surveys. We also compute the averaged expansion rate, defined by the Buchert equations, of the best fit model and show explicitly that there is no average acceleration.

show abstract

“…There exists a large body of literature on cosmological models relying on the LTB dynamics, see, e.g., [22][23][24][25][26][27][28][29][30]. Our interest here is not primarily whether or not these inhomogeneous models can provide viable alternatives to the standard ΛCDM model.…”

Section: Lemaître-tolman-bondi (Ltb) Dynamicsmentioning

confidence: 99%

Averaged Lemaître–Tolman–Bondi dynamics

Isidro¹,

Barbosa²,

Piattella³

et al. 2016

Class. Quantum Grav.

View full text Add to dashboard Cite

We consider cosmological backreaction effects in Buchert's averaging formalism on the basis of an explicit solution of the Lemaître-Tolman-Bondi (LTB) dynamics which is linear in the LTB curvature parameter and has an inhomogeneous bang time. The volume Hubble rate is found in terms of the volume scale factor which represents a derivation of the simplest phenomenological solution of Buchert's equations in which the fractional densities corresponding to average curvature and kinematic backreaction are explicitly determined by the parameters of the underlying LTB solution at the boundary of the averaging volume. This configuration represents an exactly solvable toy model but it does not adequately describe our "real" Universe. *

show abstract

Is Dark Energy the Only Solution to the Apparent Acceleration of the Present Universe?

Abstract: Even for the observed luminosity distance DL(z), which suggests the existence of dark energy, we show that an inhomogeneous dust universe solution without dark energy is possible in general. Future observation of DL(z) for 1 < ∼ z < 1.7 may confirm or refute this possibility.

Cited by 143 publications

References 15 publications

A (giant) void is not mandatory to explain away dark energy with a Lemaître-Tolman model

A (giant) void is not mandatory to explain away dark energy with a Lemaître-Tolman model

The effect of inhomogeneous expansion on the supernova observations

Averaged Lemaître–Tolman–Bondi dynamics

Contact Info

Product

Resources

About