Quick search Find article
Quick search
Find article

A counterexample to claimed COBE constraints on compact toroidal universe models

Boudewijn F Roukema

Show affiliations


It has been suggested that if the Universe satisfies a flat, multiply connected, perturbed Friedmann-Lemaître model, then cosmic microwave background data from the COBE satellite implies that the minimum size of the injectivity diameter (shortest closed spatial geodesic) must be larger than about (2/5) of the horizon diameter. To show that this claim is misleading, a simple T2×R universe model of injectivity diameter a quarter of this size, i.e. a tenth of the horizon diameter, is shown to be consistent with COBE four-year observational maps of the cosmic microwave background. This is done using the identified circles principle.


PACS

98.70.Vc Background radiations

98.80.Es Observational cosmology (including Hubble constant, distance scale, cosmological constant, early Universe, etc)

MSC

83F05 Cosmology

Subjects

Gravitation and cosmology

Astrophysics and astroparticles

Dates

Issue 19 (7 October 2000)

Received 20 September 1999, in final form 5 January 2000



  1. A counterexample to claimed COBE constraints on compact toroidal universe models

    Boudewijn F Roukema 2000 Class. Quantum Grav. 17 3951

  2. Intrinsic Properties of the Young Stellar Object SU Aurigae

    L. E. DeWarf et al. 2003 ApJ 590 357

  3. Elimination of systematic errors in two-mode laser telemetry

    C Courde et al 2009 Meas. Sci. Technol. 20 127002

  4. A structural study of praseodymium gallate glasses by combined neutron diffraction, molecular dynamics and EXAFS techniques

    P Kidkhunthod and A C Barnes 2009 J. Phys.: Conf. Ser. 190 012076

  5. X-Radiation from the Millisecond Pulsar J0437–4715

    V. E. Zavlin et al. 2002 ApJ 569 894

  6. Asymmetric universal amplitude relation and its applications in two-dimensional systems

    M J Martins 1993 J. Phys. A: Math. Gen. 26 L877

  7. A quartz crystal sensor oscillator appropriate for highly viscous liquid measurements

    I D Avramov 2009 Meas. Sci. Technol. 20 124006

  8. Dissociative recombination of CF+: Experiment and theory

    O Novotný et al 2009 J. Phys.: Conf. Ser. 192 012021

  9. Deformed spaces and loop cosmology

    Marco Valerio Battisti 2009 J. Phys.: Conf. Ser. 189 012005

  10. An all-polymer airflow sensor using a piezoresistive composite elastomer

    Avishek R Aiyar et al 2009 Smart Mater. Struct. 18 115002

View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.