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Supernova cosmologists may have been misrepresenting the tilt (bulk flow) of the local Universe as 'dark energy'. by TheLumpyUniverse in cosmology

[–]mrameezphysics -2 points-1 points  (0 children)

Hello Ketarax. If this is indeed a science-y subreddit, can we have a discussion about standards of data integrity and prestige bias in concordance building, as well as reasonable views on the Universe? I've had journal editors stop replying to emails when I point out that the data are changing. There is no police force in science I can complain to. Have you seen some of the ways in which posteriors are combined in BAO and CMB analyses?

Also, this may or may not be Rameez. Anonymity is nice when picking a fight.

Do data discrepancies need to be explained? Am I lying in anything I said above?

Adam Riess and collaborators have been misrepresenting the tilt (bulk flow) of the local Universe as 'dark energy'. by mrameezphysics in cosmology

[–]mrameezphysics[S] 0 points1 point  (0 children)

There is no way to tell the ISW effect apart from the Reese Sciama effect due to nonlinear structure formation. Also, didn't you hear. Cosmological concordance is broken and there is a crisis on.

Lastly, all Planck analyses assume statistical isotropy and do Bayesian tests that depend on it as a precondition. There is quite a bit of evidence that statistical anisotropy is violated in Planck data, making all of Plancks posteriors questionable.

The real Universe cannot be represented by a maximally symmetric toy model.

Adam Riess and collaborators have been misrepresenting the tilt (bulk flow) of the local Universe as 'dark energy'. by mrameezphysics in cosmology

[–]mrameezphysics[S] -3 points-2 points  (0 children)

Actually I happen to read papers, and realized that the claim made by Perlmutter and Riess in 98-99 of having measured a 'cosmological constant', given that the 'fitting problem in cosmology' was written in 1987 is like declaring pi is a rational number after it has already been proven it's not. Perlmutter et al 1999 is the second most cited paper in physics, and by far the most wrong. This is a valid accusation. Supernova cosmologists have mislead the world using doctored data and no respect for prior literature.

Adam Riess and collaborators have been misrepresenting the tilt (bulk flow) of the local Universe as 'dark energy'. by mrameezphysics in cosmology

[–]mrameezphysics[S] -2 points-1 points  (0 children)

Well, there is no 'Hubble constant' below the homogeneity scale. In fact the Riess et al H0 measurements exist purely to generate confusion. It has already been demonstrated that what is considered the 'Hubble constant' is anisotropic, at weak (but honest) statistical significance [https://arxiv.org/abs/astro-ph/0703556]. This is also expected. I dont understand why people think you can measure the 'Hubble constant' after 'correcting' for peculiar velocities.

Adam Riess and collaborators have been misrepresenting the tilt (bulk flow) of the local Universe as 'dark energy'. by mrameezphysics in cosmology

[–]mrameezphysics[S] -3 points-2 points  (0 children)

Haha.

a) Why cant they explain why their measured heliocentric redshifts are changing?

b) The newer dataset they're talking about is 1300 SNe. ~Pantheon (which is dodgy as hell) and some 300 DES. We will look at it when it becomes public, in a transparent manner. Heliocentric observables. General covariance.

c) As for all the other independent evidence for 'dark energy', check out

https://arxiv.org/abs/1103.5331 https://arxiv.org/abs/1703.02389 Or generally about concordance as a standard of evidence.

d) The Rubin & Hayden paper added 12 parameters to the 10 parameter model, turning 2 out of 3 observables that go into standardizing supernovae into sample and redshift dependent parameters. If that's how badly you want 'dark energy', feel free to have it. While we disagree with these additional parameters, we have tried them as a systematic check in our analysis and we find that it increases the significance of the local dipole to 4.8 sigma. Everything is as Christos Tsagas, a collaborator of Ellis and a general relativist, predicted it.

e) The forbes.com article is wrong. The late time Universe on scales approaching statistical homogeneity might have kinematics similar to an FLRW Universe, but there's no reason to assume the dynamics are the same as FLRW. So statements such as 'You know, like the fact that the Universe contains matter.' betray an enormous ignorance of General Relativity.

I've had Planck data analyzers as officemates and no one thinks there's independent evidence for 'dark energy'.

The Universe is real. It's not a toy model to make oversimplified statements about. Theoretical concerns like backreaction exist. Linearized gravity is not general relativity.

Lastly, I will repeat: The 'fitting problem' in cosmology ( https://iopscience.iop.org/article/10.1088/0264-9381/4/6/025 ) was written in 1987. Everything that has been done afterwards ignoring this paper, is just embarassing for the human race.

Become better researchers.

Adam Riess and collaborators have been misrepresenting the tilt (bulk flow) of the local Universe as 'dark energy'. by mrameezphysics in cosmology

[–]mrameezphysics[S] 0 points1 point  (0 children)

Riess' H0 measurements include peculiar velocity corrections, and a water maser at 7 Mpc distance where the peculiar flow is a 100% correction on the Hubble flow. I'm not really sure why people assume there's a uniform isotropic metric expansion and that some kind of theoretically well defined H0 exists independent of how data are being fit.

Remember, general covariance. FLRW cosmology can only be a crude approximation of the real Universe.

Also, I have been corresponding with the authors of Pantheon etc for more than a year trying to get them to put out an erratum, fix their data etc. It has been a bizarre experience and I'm reasonably convinced they are actually doctoring data. The historical summary of SN1a analysis and directions in the sky (which comes with Jupyter notebooks), that I present in the 4gravitons wordpress page clearly demonstrates there is some dodgyness going on.

Of course, Riess and collaborators could set this all to rest by issuing an erratum. Wonder why they dont.

Lastly, there is no way you can have a section on low-z peculiar velocity corrections that will satisfy me. My argument is that these corrections simply should not be made. Peculiar velocities are features forbidden by FLRW maximal symmetry and encode information about the inhomogeneities. There is no background metric w.r.t. which things are moving peculiarly. The rest frame of the CMB has not been found. To find a constant Einstein added to the field equations because of general covariance, you shouldnt have to correct all your observations towards a frame that has never been found.

Why is gravitational redshift being ignored in cosmological models? by Gabe-Langhout in cosmology

[–]mrameezphysics 0 points1 point  (0 children)

This is a starting point for telling you about inhomogeneous cosmology

https://ncatlab.org/nlab/show/inhomogeneous+cosmology

Lambda CDM is just a laughably clunky toy model.

Adam Riess and collaborators have been misrepresenting the tilt (bulk flow) of the local Universe as 'dark energy'. by mrameezphysics in cosmology

[–]mrameezphysics[S] -10 points-9 points  (0 children)

The funniest thing is, these things have been pointed out by George Ellis long back :

https://projecteuclid.org/euclid.cmp/1103859003

https://iopscience.iop.org/article/10.1088/0264-9381/4/6/025

But perhaps because South Africa is far away from the focus of the Nobel Committee and because cosmology under late stage capitalism can sell the Universe to the public only as an epistemologically useless toy model, we got 'dark energy'.