Student or educator? Sign up with your school email and get 6 months of Pro free.
Cited by 465

The DOI matches its Crossref record; 18 of the 18 references it cites were found in a registry or an index.

Cardassian expansion: a model in which the universe is flat, matter dominated, and accelerating

Open access
Freese, Katherine, Lewis, Matthew·2002·Physics Letters B

Abstract

Abstract A modification to the Friedmann–Robertson–Walker equation is proposed in which the universe is flat, matter dominated, and accelerating. An additional term, which contains only matter or radiation (no vacuum contribution), becomes the dominant driver of expansion at a late epoch of the universe. During the epoch when the new term dominates, the universe accelerates; we call this period of acceleration the Cardassian era. The universe can be flat and yet consist of only matter and radiation, and still be compatible with observations. The energy density required to close the universe is much smaller than in a standard cosmology, so that matter can be sufficient to provide a flat geometry. The new term required may arise, e.g., as a consequence of our observable universe living as a 3-dimensional brane in a higher-dimensional universe. The Cardassian model survives several observational tests, including the cosmic background radiation, the age of the universe, the cluster baryon fraction, and structure formation.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1016/s0370-2693(02)02122-6

Cites

18 of 18 references verified0 citation errors · 0 not checkable

Statistics

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cites

Show all 18 references

Cited by

See all 465

Metadata

Authors
Freese, K., & Lewis, M.
Venue
Physics Letters B
Publisher
Elsevier BV
Published
2002-07
Volume
540
Issue
1-2
Pages
1-8
ISSN
0370-2693 (ISSN-L)
OpenAlex
W2146538527
Cited by
465
References
18
FWCI
23.27
Type
journal article
Language
en
Open access
green

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review

How to cite

Cite CoChat for the checks on this page, and the paper for its own findings.

This page
CoChat. (2026). Citation check: Cardassian expansion: a model in which the universe is flat, matter dominated, and accelerating. https://app.cochat.ai/papers/10.1016/s0370-2693(02)02122-6
The paper
Freese, K., & Lewis, M. (2002). Cardassian expansion: a model in which the universe is flat, matter dominated, and accelerating. Physics Letters B. https://doi.org/10.1016/s0370-2693(02)02122-6

Data sources

Bibliographic data: Semantic Scholar, OpenAlex, Crossref.

Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.