Astrophysicist Discovers However Around Other Mode To Screw Yourself Over When Modifying Einstein’S Theory

Several people bring informed me that phys.org has once i time again uncritically promoted a questionable paper, inward this representative past times André Maeder from UNIGE. This even out goes dorsum to a press release past times the author’s habitation institution and has since been hyped past times a diversity of other low-quality outlets.

From what I get together from Maeder’s listing of publications, he’s an astrophysicist who latterly had the persuasion to revolutionize cosmology past times introducing a alteration of full general relativity. The newspaper which at nowadays makes headlines studies observational consequences of a model he introduced inward January as well as claim to explicate away the bespeak for nighttime thing as well as nighttime energy. Both papers comprise a lot of fits to information but no consistent theory. Since the homo is known inward the astrophysics community, however, the papers got published inward ApJ, i of the best journals inward the field.

For those of yous who but desire to know whether yous should pay attending to this novel variant of modified gravity, the answer is no. The writer does non bring a consistent theory. The math is wrong.

For those of yous who empathise the math as well as desire to know what the occupation is, hither nosotros go.

Maeder introduces a conformal prefactor inward front end of the metric. You tin ever exercise that every bit an ansatz to solve the equations, therefore at that topographic point is null modified close this, but too null wrong. He as well as therefore looks at empty de Sitter space, which is conformally flat, as well as extracts the prefactor from there.

He as well as therefore uses the same ansatz for the Friedmann Robertson Walker metric (eq 27, 28 inward the commencement paper). Just looking at these equations yous encounter instantly that they are underdetermined if the conformal component (λ) is a grade of freedom. That’s because the conformal component tin unremarkably endure fixed past times a approximate status as well as endure chosen to endure constant. That of course of written report would exactly laissez passer on dorsum criterion cosmology as well as Maeder doesn’t desire that. So he instead assumes that this component has the same shape every bit inward de Sitter space.

Since he doesn’t bring a dynamical equation for the extra field, my best guess is that this effectively amounts to choosing a weird fourth dimension coordinate inward criterion cosmology. If yous don’t desire to translate it every bit a gauge, as well as therefore an equation is missing. Either agency the claims which follow are wrong. I can’t tell which is the representative because the equations themselves exactly appear from nowhere. Neither of the papers comprise a Lagrangian, therefore it remains unclear what is a grade of liberty as well as what isn’t. (The model is too of course of written report non scale invariant, therefore somewhat of a misnomer.)

Maeder afterward too uses the same de Sitter prefactor for galactic solutions, which makes fifty-fifty less sense. You shouldn’t endure surprised that he tin agree exactly about observations when yous lay inward the scale of the cosmological constant to galactic models, because nosotros bring known this link since the 1980s. If at that topographic point is something novel to larn here, it didn’t run clear to me what.

Maeder’s papers bring a remarkable issue of observational fits as well as pretty plots, which I guess is why they got published. He clearly knows his stuff. He too clearly doesn’t know a lot close modifying full general relativity. But I do, therefore allow me tell yous it’s hard. It’s actually hard. There are a thou ways to screw yourself over alongside it, as well as Maeder exactly discovered the i thou as well as commencement one.

Please halt hyping this paper.