902 citations · 1.1k across the 17 of their papers we have counts for
10 papers · 1 filter
A short answer to critics of our article "Eppur si espande" [arXiv:astro-ph/0612155]
Marek A. Abramowicz, Stanislaw Bajtlik, Jean-Pierre Lasota +1
Recently [arXiv:astro-ph/0612155] we presented a formal mathematical proof that, contrary to a widespread misconception, cosmological expansion cannot be understood as the motion o…
The twin paradox on the photon sphere
Marek A. Abramowicz, Stanislaw Bajtlik, Wlodek Kluzniak
We consider a new version of the twin paradox. The twins move along the same circular free photon path around the Schwarzschild center. In this case, despite their different veloci…
Eppur si espande
Marek A. Abramowicz, Stanislaw Bajtlik, Jean-Pierre Lasota +1
The rather wide-spread belief that cosmological expansion of a flat 3D--space (with spatial curvature k=0) cannot be observationally distinguished from a kinematics of galaxies mov…
A weak acceleration effect due to residual gravity in a multiply connected universe
Boudewijn F. Roukema, Stanislaw Bajtlik, Marek Biesiada +2
Could cosmic topology imply dark energy? We use a weak field (Newtonian) approximation of gravity and consider the gravitational effect from distant, multiple copies of a large, co…
Cosmic crystallography using short-lived objects - active galactic nuclei
Andrzej Marecki, Boudewijn F. Roukema, Stanislaw Bajtlik
Cosmic crystallography is based on the principle that peaks in the pair separation histogram (PSH) of objects in a catalogue should be induced by the high number of topologically l…
A Hint of Poincaré Dodecahedral Topology in the WMAP First Year Sky Map
Boudewijn F. Roukema, Bartosz Lew, Magdalena Cechowska +2
Luminet et al. (2003) suggested that WMAP data are better matched by a Poincaré dodecahedral FLRW model of global geometry, rather than by an infinite flat model. The analysis by C…
Topological Lensing: Is the Matter Both Here and There?
B. F. Roukema, A. Marecki, S. Bajtlik +1
If the Universe satisfies a perturbed Friedmann-Lema\^ıtre model, then the bright matter (e.g. radio-loud active galactic nuclei, RLAGNs) may be topologically lensed by global geom…
Where the Very Bright Matter is a Standard Ruler
B. F. Roukema, G. A. Mamon, S. Bajtlik
Where's the matter? The answer seems to be: ``distributed according to a power spectrum with at least one feature (local maximum) near 120-130h^-1Mpc''. Analyses of the Iovino, Clo…
Transverse Galaxy Velocities from Multiple Topological Images
Boudewijn F. Roukema, Stanislaw Bajtlik
The study of the kinematics of galaxies within clusters or groups has the limitation that only one of the three velocity components and only two of the three spatial components of…
Galaxy Clustering at z ~ 2 and Halo Radii
Boudewijn F. Roukema, David Valls-Gabaud, Bahram Mobasher +1
The amplitude of the angular two-point galaxy correlation function w(θ) for galaxies at z~2 is estimated for galaxies in the Hubble Deep Field by using a U < 27 complete sub-sample…