Not signed in (Sign In)

Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

  • Sign in using OpenID

Site Tag Cloud

2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry book bundles calculus categorical categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology colimits combinatorics complex complex-geometry computable-mathematics computer-science constructive cosmology definitions deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry digraphs duality elliptic-cohomology enriched fibration foundation foundations functional-analysis functor gauge-theory gebra geometric-quantization geometry graph graphs gravity grothendieck group group-theory harmonic-analysis higher higher-algebra higher-category-theory higher-differential-geometry higher-geometry higher-lie-theory higher-topos-theory homological homological-algebra homotopy homotopy-theory homotopy-type-theory index-theory integration integration-theory k-theory lie-theory limits linear linear-algebra locale localization logic mathematics measure-theory modal modal-logic model model-category-theory monad monads monoidal monoidal-category-theory morphism motives motivic-cohomology nforum nlab noncommutative noncommutative-geometry number-theory of operads operator operator-algebra order-theory pages pasting philosophy physics pro-object probability probability-theory quantization quantum quantum-field quantum-field-theory quantum-mechanics quantum-physics quantum-theory question representation representation-theory riemannian-geometry scheme schemes set set-theory sheaf simplicial space spin-geometry stable-homotopy-theory stack string string-theory superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory tqft type type-theory universal variational-calculus

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to nForum
If you want to take part in these discussions either sign in now (if you have an account), apply for one now (if you don't).
    • CommentRowNumber1.
    • CommentAuthorSpacenumbat
    • CommentTimeDec 31st 2021
    Hi,

    I am a layperson who has read all the popular books about String theory and my hobby right now is trying to get a better sense of what is happening at the frontier. I have been reading here that Hypothesis H could lead to a full understanding of M-theory. I have also been reading recently about matrix models. Wikipedia says that the authors BFSS claim their matrix model is exactly equivalent to M-theory. I also read recently that the IKKT matrix model, which models the Type IIb string theory and not the full m-theory, has been claimed to dynamically compactify the extra dimensions making our spacetime emergent, and thereby avoiding the problem of the landscape of vacua of string theory.

    My question is whether these ideas are in conflict or are they compatible. If Hypothesis H is true and it completes m-theory, would it render the IKKT matrix model invalid or obsolete or, conversely, is it plausible that Hypothesis H would independently reproduce the IKKT model's result of spontaneously compactifying the extra dimensions.

    I have more questions too, but I will leave those for another thread. Thank you so much for your time!
    • CommentRowNumber2.
    • CommentAuthorUrs
    • CommentTimeDec 31st 2021
    • (edited Dec 31st 2021)

    It should all be compatible in the end, keeping in mind the limits of available proposals.

    For instance, we found that:

    • the Green-Schwarz action functional for the supermembrane (whose regularized quantization is the BFSS matrix model) is part of the rational equivariant Cohomotopy data postulated by Hypothesis H (this is Prop. 6.10 in Sec. 6.2 of arXiv:1805.05987);

    • the quantum ground states of the BMN version of the BFSS matrix model are plausibly seen among the quantum states of M-theory according to Hypothesis H – this is the content of Sec. 4.9 of arXiv:1912.10425,

      I touch upon this in my recent talk Some Quantum States of M-Branes under Hypothesis H.

    But one should note that there are still limitations on both sides:

    (1) The BFSS matrix model is thought to see some corner of M-theory, but not the full thing (references here). For instance the BMN matrix model is a generalization/deformation of the BFSS model which clearly sees a different corner of M-theory.

    (2) We haven’t really pushed for a full definition of M-theory via Hypothesis H just yet. Most of the checks we made so far concern differential-topological conditions of the flux fields over classical background spacetimes. From there we started exploring the quantum implications of the Hypothesis in arXiv:1912.10425 and arXiv:2105.02871, but this is not meant to be complete yet.

    Notably, these discussions of Hypothesis H concern only the C-field so far, ignoring the field of (super-)gravity. It is hence clear that this cannot be the full picture yet, and that there is more detailed implications of Hypothesis H to be worked out. We think we know how to include the metric field (this is briefly indicated on slide 14 here) but analyzing this in detail remains to be done.

    • CommentRowNumber3.
    • CommentAuthorSpacenumbat
    • CommentTimeDec 31st 2021
    This is great, thank you very much!