Discoveries using the telescopes on Mauna Kea

[TomK]

Kenney - https://video.pbshawaii.org/video/3008168895/

[TomK]

Our dysfunctional solar system

It seems our own solar system is a bit of a mess compared to others. They seem to keep their own regions a little more respectful and orderly. Most other solar systems seem to consist of planets of roughly similar sizes and equal distances apart whereas ours consists of planets of all sorts of sizes and various distances between them. Why?

It's likely that in our solar system, the giant gas planets Jupiter and Saturn formed early and their gravitational forces then affected the formation of other planets, including the Earth.

It's a bit early to say if this is the case, but it's certainly interesting. The observations that led to this conclusion were made at the Keck Observatory on Mauna Kea.

https://phys.org/news/2018-01-planets-st...s-pod.html

"The similar sizes and orbital spacing of planets have implications for how most planetary systems form. In classic planet formation theory, planets form in the protoplanetary disk that surrounds a newly formed star. The planets might form in compact configurations with similar sizes and a regular orbital spacing, in a manner similar to the newly observed pattern in exoplanetary systems. However, in our solar system, the inner planets have surprisingly large spacing and diverse sizes. Abundant evidence in the solar system suggests that Jupiter and Saturn disrupted our system's early structure, resulting in the four widely-spaced terrestrial planets we have today. That planets in most systems are still similarly sized and regularly spaced suggests that perhaps they have been mostly undisturbed since their formation."

[oink]

Tom, did you guys have anything to do with this research? : Study reveals substantial evidence of holographic universe ( https://knowridge.com/2018/01/study-reve...-universe/ ) Do you understand it at all? Does it explain Puna?

Pua`a
S. FL
Big Islander to be.

[HereOnThePrimalEdge]

Janna Levin, host of Black Hole Apocolypse is answering questions in an AMA on Reddit:
https://amp.reddit.com/r/science/comment...ssion=true

"This is an island surrounded by water, big water, ocean water.” - President Donald J. Trump

[Kenney]

Mahalo Tom, HTOPE.

[TomK]

Oink,

As far as I'm aware, that research didn't include any observatories or staff at the MK observatories. The observational part of the project looked at the cosmic microwave background which, as you might guess, involves telescopes that work at that wavelength, and MK doesn't have any that are specifically designed for that.

I'm not a cosmologist, but the paper the article refers to (I think) is this:

https://arxiv.org/abs/1607.04878

And in the abstract, which only a cosmologist could write:

"By comparing the Bayesian evidence for the models, we find that (Lambda)CDM does a better job globally, while the holographic models provide a (marginally) better fit to data without very low multipoles (i.e. l<=30), where the dual QFT becomes non-perturbative."

they actually say that standard models of the universe are generally a better fit to the data than the holographic models. So I think it's all a bit of hype right now.

PS. I had to edit a couple of characters in the abstract as they didn't work on PW.

[oink]

quote:

---

"By comparing the Bayesian evidence for the models, we find that (Lambda)CDM does a better job globally, while the holographic models provide a (marginally) better fit to data without very low multipoles (i.e. l<=30), where the dual QFT becomes non-perturbative."

---

Say what?

Pua`a
S. FL
Big Islander to be.

[TomK]

As I said, it was written by a cosmologist. That's actually the "easiest" sentence to understand, you're fortunate I didn't quote the whole abstract, which says:

"We test a class of holographic models for the very early universe against cosmological observations and find that they are competitive to the standard (Lambda)CDM model of cosmology. These models are based on three dimensional perturbative super-renormalizable Quantum Field Theory (QFT), and while they predict a different power spectrum from the standard power-law used in (Lambda)CDM, they still provide an excellent fit to data (within their regime of validity). By comparing the Bayesian evidence for the models, we find that (Lambda)CDM does a better job globally, while the holographic models provide a (marginally) better fit to data without very low multipoles (i.e. l<=30), where the dual QFT becomes non-perturbative. Observations can be used to exclude some QFT models, while we also find models satisfying all phenomenological constraints: the data rules out the dual theory being Yang-Mills theory coupled to fermions only, but allows for Yang-Mills theory coupled to non-minimal scalars with quartic interactions. Lattice simulations of 3d QFT's can provide non-perturbative predictions for large-angle statistics of the cosmic microwave background, and potentially explain its apparent anomalies."

Maybe that's a little clearer?

Personally, I prefer not being a cosmologist, I think it can do harm to your mental health...

[TomK]

This should clear things up.

Bzowksi et al, 2012:

"We provide a precise and quantitative holographic description of a class of inflationary slow-roll models. The dual QFT is a deformation of a three-dimensional CFT by a nearly marginal operator, which, in the models we consider, generates an RG flow to a nearby IR fixed point. These models describe hilltop inflation, where the inflaton rolls from a local maximum of the potential in the infinite past (corresponding to the IR fixed point of the dual QFT) to reach a nearby local minimum in the infinite future (corresponding to the UV of the dual QFT). Through purely holographic means, we compute the spectra and bispectra of scalar and tensor cosmological perturbations. The QFT correlators to which these observables map holographically may be calculated using conformal perturbation theory, even when the dual QFT is strongly coupled. Both the spectra and the bispectra may be expressed this way in terms of CFT correlators that are fixed, up to a few constants, by conformal invariance. The form of slow-roll inflationary correlators is thus determined by the perturbative breaking of the de Sitter isometries away from the fixed point. Setting the constants to their values obtained by AdS/CFT at the fixed point, we find exact agreement with known expressions for the slow-roll power spectra and non-Gaussianities."

QED. Any questions?

[oink]

Thanks for taking time for such a through response, I think. I only have one thing to say. Uncle!

Pua`a
S. FL
Big Islander to be.