On Sunday, October 31, 2021 at 1:34:45 PM UTC-5 jessem wrote:
> But even if low energy SUSY is ruled out, isn't it possible that > supersymmetric particles would exist but at much higher energies than the > LHC can reach, and if so couldn't such particles still fill the role of > WIMPs in dark matter theories? That's what I was saying about the landscape > model in string theory, I thought that at least some advocates of the > landscape believed in supersymmetry but saw no particular reason to believe > it would be a low-energy version that would solve the hierarchy problem. > For example, when I was looking for info on this I found this quote from p. > 259 of the book Naturalness, String Landscape and Multiverse: > > "We should emphasise, however, that low-scale SUSY is certainly not a > prediction of string theory. 10d stringy SUSY may be broken directly in the > compactification process (e.g. through a non- Calabi–Yau compactification) > or at any energy scale between KK-scale and weak scale." > That is entirely my thesis. Supersymmetry is a quantum gravitational physics. LC > > On Sun, Oct 31, 2021 at 9:06 AM Lawrence Crowell <[email protected]> > wrote: > >> The whole low energy SUSY theory appears to be in trouble. The breaking >> of SUSY as the TeV scale appears not to work. This eliminates the >> neutralino, which is a condensate of supersymmetric partners of the Z >> particle and photon, appears to not exist. This does remove to a fair >> degree a SUSY predicted WIMP particle, the neutralino. >> >> LC >> >> On Friday, October 29, 2021 at 10:20:20 AM UTC-5 jessem wrote: >> >>> When you say "WIMPs are most likely ruled out" is that related to >>> failure to find supersymmetric particles at LHC? (Correct me if I'm wrong, >>> but my understanding was that many physicists hoped supersymmetry would >>> solve the 'naturalness problem' of the weak energy scale in a way that >>> required supersymmetric particles to have masses in that range, but >>> advocates of the landscape model like Susskind thought there needn't be any >>> 'explanation' for the energy scales of different forces beyond the >>> anthropic principle.) Or are there other reasons to rule them out, like >>> cosmological simulations based on WIMPs being unable to match certain >>> cosmological observations about the real universe? >>> >>> Jesse >>> >>> On Fri, Oct 29, 2021 at 7:15 AM Lawrence Crowell < >>> [email protected]> wrote: >>> >>>> On Thursday, October 28, 2021 at 9:08:55 PM UTC-5 [email protected] >>>> wrote: >>>> >>>>> Lawrence, any guesses as to what Dark Matter could be? Nobody can >>>>> find any evidence of WIMPS and now sterile neutrinos seems to have >>>>> bit the dust. Would you bet your money on Axions, or some modification of >>>>> General Relativity (teleparallel gravity perhaps) or none of the above? >>>>> >>>>> John K Clark >>>>> >>>>> ========== >>>>> >>>>> >>>>> >>>> I have no commitment to any particular theory. Dark matter might turn >>>> out to be some new physics involving mass-energy in an entirely different >>>> form from what we traditionally know as particles or fields. Dark energy >>>> is >>>> most likely some sort of vacuum energy, where the big unknown is how the >>>> vacuum energy is so small compared to what QFT predicts. Dark matter is >>>> not >>>> homogeneous and isotropic as is dark energy that is presumed to give the >>>> de >>>> Sitter-like expansion curvature. Yet it is still possible that dark energy >>>> is some vacuum type of physics. I have pondered that the large energy >>>> excess we expect for dark energy might in fact be some localized form of >>>> vacuum energy that condensed in the early universe, and this excess >>>> remains >>>> as DM. >>>> >>>> The phenomenologies proposed so far seem to be falling apart. WIMPs are >>>> mostly likely ruled out. Sterile neutrinos appear to be gone. Axions >>>> remain >>>> a possibility, though so far attempts to detect them have come up null. As >>>> a result the most honest thing that can be said is we really have no >>>> certainty about the nature of DM. >>>> >>>> LC >>>> >>>> -- >>>> >>> You received this message because you are subscribed to the Google >>>> Groups "Everything List" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> >>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/everything-list/f24dd18e-7185-4cf5-88a7-9e3444da6642n%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/everything-list/f24dd18e-7185-4cf5-88a7-9e3444da6642n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "Everything List" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/everything-list/e126d7f2-a194-4a6b-80f7-757e38088b00n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/everything-list/e126d7f2-a194-4a6b-80f7-757e38088b00n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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