KATRIN rules out light sterile neutrinos as dark matter

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KATRIN rules out light sterile neutrinos as dark matter

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Post by notFritzArgelander »


Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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Re: KATRIN rules out light sterile neutrinos as dark matter

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Post by notFritzArgelander »


It should be noted that the data are based on the first 4 week data run. After 1000 days running there will be almost no place for a sterile neutrino to hide except at greater than 1,000 ev mass equivalent.
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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Re: KATRIN rules out light sterile neutrinos as dark matter

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One caveat.....

The article reads
If sterile neutrinos are also released during radioactive decay, it would leave a visible trace in the energy spectrum of electrons.
I think that the IF there is huge! Sterile neutrinos are usually (by definition) non participants in the weak interaction. Therefore it follows that they WOULD NOT be participants in radioactive decay. Thus as useful as KATRIN will hopefully be in measuring the masses of active neutrinos, it cannot put any limits at all on the mass or existence of sterile neutrinos. It can only put limits on a 4th species of active neutrino.

https://en.wikipedia.org/wiki/Sterile_neutrino

So on further thought and proper caffeination this negative result is meaningless.
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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Re: KATRIN rules out light sterile neutrinos as dark matter

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Post by ThinkerX »


Can't remember what at the moment, but I seem to recollect some other once favored DM particle being ruled out not too long ago.

So...what candidates for DM remain? And are any of those candidates...'at risk?'
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Re: KATRIN rules out light sterile neutrinos as dark matter

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Post by notFritzArgelander »


ThinkerX wrote: Tue Apr 13, 2021 5:53 am Can't remember what at the moment, but I seem to recollect some other once favored DM particle being ruled out not too long ago.

So...what candidates for DM remain? And are any of those candidates...'at risk?'
Well, the claim of this work to rule out light sterile neutrinos would seem (see post #3) to be all hype and not at all substantiated. So I disregard it. It says nothing at all about sterile neutrinos.

SUSY WIMPs are threatened due to nonappearance at the LHC, SUSY WIMPzillas are fully viable.

Axions are ruled out only in limited ranges of mass, there's a lot of parameter space that is untested.
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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Re: KATRIN rules out light sterile neutrinos as dark matter

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Post by AntennaGuy »


notFritzArgelander wrote: Tue Apr 13, 2021 7:28 am
ThinkerX wrote: Tue Apr 13, 2021 5:53 am Can't remember what at the moment, but I seem to recollect some other once favored DM particle being ruled out not too long ago.

So...what candidates for DM remain? And are any of those candidates...'at risk?'
Well, the claim of this work to rule out light sterile neutrinos would seem (see post #3) to be all hype and not at all substantiated. So I disregard it. It says nothing at all about sterile neutrinos.

SUSY WIMPs are threatened due to nonappearance at the LHC, SUSY WIMPzillas are fully viable.

Axions are ruled out only in limited ranges of mass, there's a lot of parameter space that is untested.
Ok, so... suppose one speculated that the most likely DM candidate(s) is the "most elegant" one. Any thoughts on what would that be? (Yes, I know that's a non-trivial question. So I'm asking a non-trivial mind!)
* Meade 323 refractor on a manual equatorial mount.
* Celestron C6 SCT on a Twilight 1 Alt-Az mount
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Re: KATRIN rules out light sterile neutrinos as dark matter

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Post by notFritzArgelander »


AntennaGuy wrote: Tue Apr 13, 2021 2:32 pm
notFritzArgelander wrote: Tue Apr 13, 2021 7:28 am
ThinkerX wrote: Tue Apr 13, 2021 5:53 am Can't remember what at the moment, but I seem to recollect some other once favored DM particle being ruled out not too long ago.

So...what candidates for DM remain? And are any of those candidates...'at risk?'
Well, the claim of this work to rule out light sterile neutrinos would seem (see post #3) to be all hype and not at all substantiated. So I disregard it. It says nothing at all about sterile neutrinos.

SUSY WIMPs are threatened due to nonappearance at the LHC, SUSY WIMPzillas are fully viable.

Axions are ruled out only in limited ranges of mass, there's a lot of parameter space that is untested.
Ok, so... suppose one speculated that the most likely DM candidate(s) is the "most elegant" one. Any thoughts on what would that be? (Yes, I know that's a non-trivial question. So I'm asking a non-trivial mind!)
Using the metric of ‘solving the most problems with a single particle’ for example then it would be the axion. One solves the Dark Matter and excess of matter over antimatter problems at once.

Another metric would be ‘mathematical beauty’ and in that case it’s SUSY WIMPs or WIMPzillas. All string theory is dead as a program if SUSY particles aren’t found. String theory cannot work without them.

Now string theory is an approach to quantum gravity that starts from the POV that quantum field theory is more fundamental than spacetime geometry. It’s interesting that if you start from the other POV, that spacetime geometry is more fundamental, that one arrives at the same number of extra spatial dimensions as string theory needs to be free of singularities. What if the opposing POVs are reconcilable as a duality? Then mathematical beauty and the excess of matter can both be served by Kaluza-Klein particles that serve as axions and as SUSY particles as well.

See the Dr H videos (1 down and 1 coming) on extra dimensions for Kalisz-Klein geometry to replace the standard model.
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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Re: KATRIN rules out light sterile neutrinos as dark matter

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Post by AntennaGuy »


If there really exist 11 dimensions, but most of them are compactified, then here's some wild/speculative (and admittedly uninformed and naive) questions, which I hope you will entertain (thank you!):
1. Other than by asserting the Anthropic Principle (which is much like cheating, after all), is there a good/elegant reason that most of the dimensions of spacetime are/should be compactified, while a specific few of them are not?
2. By any chance, would/could it be reasonable to interpret the Big Bang as corresponding specifically to an 11-dimensional fully-compactified universe undergoing inflation of 3 (or 4) of its 11 dimensions, while still keeping the rest compact? If so, could those currently compact dimensions likewise suddenly or independently expand? Could a universe obeying the "same rules" (at a very high level) as our own exist with a different balance, in terms of the number of expanded vs. the number of compactified dimensions?
* Meade 323 refractor on a manual equatorial mount.
* Celestron C6 SCT on a Twilight 1 Alt-Az mount
Prof. Barnhardt to Klaatu in The Day the Earth Stood Still: "There are several thousand questions I'd like to ask you.”
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Re: KATRIN rules out light sterile neutrinos as dark matter

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Post by notFritzArgelander »


AntennaGuy wrote: Tue Apr 13, 2021 6:45 pm If there really exist 11 dimensions, but most of them are compactified, then here's some wild/speculative (and admittedly uninformed and naive) questions, which I hope you will entertain (thank you!):
1. Other than by asserting the Anthropic Principle (which is much like cheating, after all), is there a good/elegant reason that most of the dimensions of spacetime are/should be compactified, while a specific few of them are not?
Use of the Anthropic Principle cannot be underrated IMO. Your characterization of it as cheating is overly kind, perhaps. :)

The number of compactified dimensions is related to the gauge symmetry dimensions of the associated fields. The few noncompactified dimensions have no associated gauge symmetries except, of course, in the sense that coordinate transformations in GR ARE perhaps a gauge symmetry. This last is already known to be the case: https://en.wikipedia.org/wiki/Introduct ... relativity

So it is not very speculative.
2. By any chance, would/could it be reasonable to interpret the Big Bang as corresponding specifically to an 11-dimensional fully-compactified universe undergoing inflation of 3 (or 4) of its 11 dimensions, while still keeping the rest compact? If so, could those currently compact dimensions likewise suddenly or independently expand? Could a universe obeying the "same rules" (at a very high level) as our own exist with a different balance, in terms of the number of expanded vs. the number of compactified dimensions?
OK let's get wild now..... :)

The question of whether ECSK gravity (with a Big Bounce) or GR (with a Big Bang) is the correct theory of gravity doesn't matter for this discussion. We can start with a gravity theory holding in all 11 dimensions and an inflation or expansion of all. Temperature falls as a result and first the dimensions (4) associated with the strong nuclear force freeze out and are compactified. This leaves the remaining 7 dimensions expanding and cooling until the weak (2) dimensions and electromagnetic (1) dimension freeze out successively. So the breaking of symmetry is a thermal effect that is linked to compactification.

A wild guess is that once frozen the compactification is stable unless the temperature is raised by some heroic means.

A further wild guess is that the resulting dimensional structure would be unique and that the number of natural constants of Nature would be surprisingly small.
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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