Testing for monotonicity in the Hubble diagram

General relativistic kinematics and the cosmological principle alone imply a monotonicity constraint in the Hubble diagram, which we confront to present-day supernova data. We use the running gradient method of statistical inference by Hall & Heckman (2000). We find no significant departure from monotonicity. The method seems well adapted and we recommend its use with future data.Comment: 5 pages, 3 figure

Fuzzy Mass Relations for the Higgs

The non-commutative approach of the standard model produces a relation between the top and the Higgs masses. We show that, for a given top mass, the Higgs mass is constrained to lie in an interval. The length of this interval is of the order of $m_\tau^2/m_t$.Comment: 26 pages, LaTe

On a Classification of Irreducible Almost Commutative Geometries

We classify all irreducible, almost commutative geometries whose spectral action is dynamically non-degenerate. Heavy use is made of Krajewski's diagrammatic language. The motivation for our definition of dynamical non-degeneracy stems from particle physics where the fermion masses are non-degenerate.Comment: 47 pages, 9 figure

On a weak Gauss law in general relativity and torsion

We present an explicit example showing that the weak Gauss law of general relativity (with cosmological constant) fails in Einstein-Cartan's theory. We take this as an indication that torsion might replace dark matter.Comment: 10 pages. Version 2 corrects a factor 3 in Cartan's equations to become

Comment on "Revisiting the Wu-Yang approach to magnetic charge''

In two recent papers Gonuguntla and Singleton claim that the Wu-Yang fiber bundle approach does not lead to to a consistent model for magnetic charge. We point out that this claim is false.Comment: 2 pages, no figure

Lensing in an interior Kottler solution

We derive the interior Kottler solution of the incompressible fluid and show that the bending of light in this solution does depend on the cosmological constant.Comment: The inner Kottler solution derived and used in this paper is not new. Corresponding references to Stuchlik (2000) and Boehmer (2003) are added. Also added: a numerical example and a figure. This is the version accepted by Gen. Rel. Grav. However it includes a short passage that an anonymous referee had me suppress

A Farewell To Unimodularity

We interpret the unimodularity condition in almost commutative geometries as central extensions of spin lifts. In Connes' formulation of the standard model this interpretation allows to compute the hypercharges of the fermions.Comment: LaTeX, 16 pages, Dedicated to the memory of Daniel Testar

Torsion, an alternative to the cosmological constant?

We confront Einstein-Cartan's theory with the Hubble diagram and obtain a negative answer to the question in the title. Contrary findings in the literature seem to stem from an error in the field equations.Comment: 10 pages, 1 figure. Version 2 corrects a factor 3 in Cartan's equations to become