Jenny Lorraine Nielsen is developing a novel, mathematically grounded theory of quantum gravity using topological methods.
The paper is currently under peer review, but she’d welcome any thoughts or feedback from members who have time to take a look:
The Topological Unified Field Theory on the Complex Hopf Fibration S1 → S9 → CP4
Author here -- I would be happy to answer any questions or address any points of contention! 
Any and all feedback much appreciated!
The mechanism that collapses from 9D to observable 4D is sketched but not dynamically derived, right? How are unwanted Kaluza-Klein modes suppressed without fine-tuning?
Also, the paper starts without a metric, normalising the Laplacian (or deciding what counts as “unit” flux) quietly imports geometric information. Where does that metric choice come from?
If the overall scale is ultimately fixed by comparing one predicted constant to experiment, then the other predictions are not parameter-free, right?. How many independent empirical inputs does the paper really need to calibrate its spectra before it matches the observed constants?
On Dimensional Reduction and Kaluza-Klein Modes
Q: The mechanism that collapses from 9D to observable 4D is sketched but not dynamically derived, right? How are unwanted Kaluza-Klein modes suppressed without fine-tuning?
A: The dimensional reduction mechanism is dynamically derived in the section on the Lagrangian/Action/Dynamics. By setting higher dimensional influences to zero, the effective 4D dynamics come into focus. The stuff happening on higher dimensions really doesn't have to be suppressed because it's higher level gauge theory stuff, but if you're only interested in 3D mechanical dynamics, you don't "need it".
Unlike traditional Kaluza-Klein theories, this model does not rely on compactified extra dimensions with Fourier modes. The higher-dimensional structure encodes global consistency conditions that project coherent, lower-dimensional dynamics rather than producing a tower of KK excitations. Hence, no fine-tuned suppression mechanism is required—such modes do not arise in this formalism. Kaluza Klein modes aren't something that naturally happens in this theory so they don't need to be suppressed.
On the Metric and Unit Flux Normalization
Q: The paper starts without a metric, but normalising the Laplacian or defining “unit” flux seems to import one. Where does the metric choice come from?
A: This theory is fundamentally a topological picture to start with, so we start with the shape of the field itself and begin without a metric. The emergence of a pseudo-metric structure arises dynamically via the constraint structure of the BF-type action and from the embedding geometry of the lower-dimensional fibers. So we basically just take a look at an effective slice of S3, which is where 3D dynamics emerge, and there's the pseudo-metric. If you could explain the context for the "unit flux" that would help.
On Parameter-Free Predictions and Empirical Inputs
Q: If the overall scale is fixed by comparing one predicted constant to experiment, are the other predictions really parameter-free? How many empirical inputs does the theory need to calibrate its spectra?
A: The theory derives the Higgs vacuum expectation value (VEV) topologically from the structure of the bundle and its knot invariants fairly early on in the paper, so I don't rederive in the constants section. The constants are all derived relative to using topological and spectral properties (e.g., normalized Chern-Simons invariants, torsion, and interference eigenvalues). No additional empirical parameters are introduced or fit by hand.
Jenny, your TUFT framework introduces an elegant topological model with rich geometric structure. In reading through your work, I have a few technical questions that I believe could help refine and further develop its physical depth. I'm presenting these in the spirit of constructive dialogue — to better understand the full scope of TUFT's predictive mechanisms, especially its transition from topological formalism to observable physics.
Could you clarify whether the reduction from 9D to 4D is dynamically derived from the action principle, or is it a postulated projection?
If it is derived, what constraints or boundary conditions enforce the collapse without compactification or symmetry breaking?
In the absence of compactification, how are unwanted degrees of freedom like Kaluza-Klein modes or residual gauge modes dynamically filtered out?
Is there a topological or spectral mechanism that enforces the selection of only the 4D observable modes?
Since TUFT begins as a topological bundle model, how does it transition to describing causal dynamics in 4D spacetime?
Are the curvature forms embedded into an effective action that generates time evolution or field equations?
Since the theory begins without a metric, where exactly does the effective 4D Lorentzian metric emerge from?
Is this metric derived from variation of the action or simply inferred from the geometry of a selected fiber (like a slice of S3)?
When you normalize flux, Laplacians, or curvature forms, does this implicitly require a choice of volume form or metric?
If so, can this metric be shown to arise from the topological data alone, or is it imported manually?
You mention deriving the Higgs vacuum expectation value and other constants topologically. How many empirical inputs are required to calibrate the theory's predicted constants?
Once one constant (such as the Higgs VEV) is fixed, are all other constants locked in automatically through topological invariants?
Or do additional experimental inputs enter through other spectral values?
Does TUFT include a natural path toward a full quantum field theory framework, such as canonical quantization or path integral formulation?
Do the bundle connections or curvature forms admit a structure that allows standard quantum operators or transition amplitudes?
The use of the first Chern class and topological entropy current is compelling — could this be expanded into a full thermodynamic or quantum statistical model of the arrow of time?
Does TUFT suggest that entropy production is topologically sourced, rather than a result of coarse-graining or probabilistic emergence?
Given the fiber-twist-modulated scale factor you derive, is there a path to match TUFT predictions to real-world cosmological features like inflation, cosmic background anomalies, or baryon asymmetry?
Could TUFT be used to model or explain observed fluctuations or modulations in the early universe?
Again, I find your framework compelling and worth deeper exploration. These questions are meant to surface areas that could strengthen its foundations.
Dear Jenny,
The proposed model has S9 as a total space, which contains Spin(10) as an isometry group. Section 2.3 states that a Riemannian metric is induced by S9's embedding in R10. The 4D spacetime metric with (3,1) signature is claimed to be reducible from this 10D metric.
Section 3.6 mentions that "The spacetime symmetry group SO(4) (or SO(1, 3) in Lorentzian signature) is a subgroup of the full gauge group SO(10) but only overlaps with a subset of its generators."
Later, on pages 40-41, it seems you actually mean to say that SO(4) overlaps with G_SM.
On page 40, you also state, "Here U(1) acts dually as the electromagnetic gauge field and as a rotation within
SO(4) spacetime."
Page 44 states, "Varying with respect to Bab imposes:
F_ab = 0,
which constrains the SO(9) connection to be flat modulo topological defects, encoding global bundle
topology rather than local metric curvature."
Questions:
1.a) How is it possible for SO(4) to simultaneously be a subgroup of SO(10), yet only interlap with a subset of its generators. By definition, if a group H is a subgroup of G, then all of the generators of H are within G.
1.b) Did you actually mean to say that there are two H_1, H_2, such that H_1 \subset G and H_2 \subset G, yet H_1 overlaps with H_2? This seems to be what you describe later.
1.c) If H_1 = G_SM and H_2 = G_spacetime, then how does one satisfy the Coleman-Mandula theorem? Field theory typically takes the non-gravitational gauge group to be separate from the spacetime gauge group, implying a direct product or no overlap between H_1 and H_2.
1.d) If G_SM, U(1)_ EM specifically, overlaps with G_spacetime, then does this mean that a local Lorentz transformation will also result in an electromagnetic gauge transformation?
2.a) How does one define the "division" operation on page 42? If direct sums are used for the algebras, why not refer to direct subtraction?
2.b) Can you provide a name for g_{unified}? Is this supposed to be so(10)? If so, there would be additional representations. If not, and a direct sum is used with some generators removed, have you verified that this gives a valid Lie algebra? It appears that you are taking the direct sum of two algebras and removing a single Cartan generator from this semi-simple Lie algebra. Typically, if one takes an algebra and removes a single generator, it is not an algebra. For instance, if a Chevalley basis is taken, one can see that two generators corresponding to two opposite roots lead to Cartan generators to close the algebra.
3) If F_ab = 0, which is the field strength for SO(9), and SO(9) is in SO(10), then how is it possible to obtain standard model dynamics with non-zero Yang-Mills field strengths? The Wu-Yang dictionary highlights how curvatures are gauge-gravitational field strengths. As such, if G_SM is in SO(10), much of this G_SM would be within SO(9). If the field strength for SO(9) is set to zero by the equations of motion, then how is it possible to obtain non-zero gluon or electroweak field strengths?
4) Eq. 95 on page 52 claims to derive the Higgs vev, as highlighted by the title of Section 3.9. After Eq. 95, the following is stated, "provided that the fiber radius satisfies R ∼ 1.48 × 10−18 m, naturally reproducing the electroweak scale
from topological first principles." Did you just use the Higgs vev to find R, and then use R to claim that the Higgs vev was derived? In other words, you could have solved for any R to allow for any value of the Higgs vev, correct?
i see an R times R namely R squared starting from page four
(By the way trying to search for the character of |R with a (bar vertical sideway standard textbook notation for real numbers) in the file is an adventure in itself )
namely the infinite flat surface
comes with a series of problems (maybe paradoxes) that mathematicians {depending on the specialization) are used to try to get rid of ignore or just don't know about them
the way see a solution is , to embrace the complexity , with the disadvantage of slowing down calculations (maybe even not being able arrive at results )
how is this real line/surface smooth? ( the terms appear later multiple time in paper)
for example
one can obtain the same number of points of a surface with a line with a zipper like construction on the decimals
this tells that there is something line like in a surface or
------------------------------- surface like in a line \\\\\\\
[...]
(i don't know for sure weather an experimental physical realisation for this exist)
going further higher sphere and projective planes could makes this notions even fuzzyers
i don't know maybe the paper is written considering all this knowledge basic
or depending how the axioms are being defined
basic avoidable paradoxes the more structural results are being searched for
are there structural (general) theorems that includes basic paradoxes ?
(maybe this what model theory is for)
Hi Jenny,
I was surprised and interested to see your TUFT paper come up here. The Hopf fibration S¹→S⁹→CP⁴ is an elegant way to package the physics, and it’s good to see someone bringing that specific geometry into the discussion.
For context, I published the Coherence Unified Field Theory (CUFT) earlier this year:
Carroll, J. G. (2025). Coherence Unified Field Theory. Zenodo. https://doi.org/10.5281/zenodo.14934264 (Published Feb 26, 2025).
CUFT lays out the general recursive engine: coherence laws, collapse regulation, feedback dynamics, symbolic constants, and projection operators into observables. In that sense, TUFT reads to me as one instance of these principles inside a Hopf embedding.
My work has since expanded recursion beyond 100 cycles, with coding rules that preserve topology at every step, and we’re systematically rewriting classical field structures — Lagrangians, Hamiltonians, gauge transformations — into recursive coherence form.
That’s why I think there’s a natural collaboration here. CUFT provides the general machinery and a validation framework plus massive research tools; TUFT offers a concrete geometric instantiation. Would love to hear from you and see how we may be able to collaborate and really bring topology based unification mainstream!
Best,
Jason
marcovici alexandru
What you say, as always, is a load of pathetic drivel.
Hi. I'm just getting into this, so I'm trying to understand the basic concept. Perhaps my confusion will be helpful to others.
We know that gage theories describe the geometry whereby the properties of one particle influence the properties of another particle. Obviously, these transformations are subject to topological analysis. I take it that topological field theory explores this mapping. I assume that much of what is described in the paper is a projection of that mapping back onto gage theory. In other words, as it arose from an analysis of gage theory, it should not be surprising that gage theory should be implied by the formal characteristics of the topology.
Space-time is involved in all particle interactions. This means that it is a unifying element of all topological analysis. This paper states that we must start with a nine-dimension space-time in order to allow sufficient freedom for the EM, weak, and color transformations to be supported.
S(1) appears to be interesting because it is known to introduce constraints upon topological transformations that in physical systems generate Coriolis forces.
If this is a correct understanding, then how do we introduce a geometry that causes these transformations to have varying strength? Similarly for masses and generations.
@"Brian Balke
Hi Brian — great questions, thanks for working through this carefully. Let me try to untangle a few points.
Gauge vs. Topology.
Gauge theory is geometric, but in TUFT the global topological structure is primary. In ordinary gauge theory you fix spacetime first and then build gauge fields on top. Here, the nontrivial bundle itself (the complex Hopf fibration S1 -> S9 -> CP4) is the foundation. Gauge groups arise as consequences of that topology, not the other way around.
Nine dimensions.
9D spacetime isn’t arbitrary — it’s the minimal shell where the Hopf structure can encode all three Standard Model interactions, particle spectra, and gravity. The extra dimensions aren’t free parameters, but a topological requirement to carry U(1), SU(2), and SU(3) twists coherently as well as particle interactions.
S1 and Coriolis intuition.
Yes, S1 fiber twists can look like Coriolis-type forces, but here it’s sharper: the S1 bundle curvature is the electromagnetic field strength, and higher twists give the weak and strong sectors. The “constraint” is that you can’t untwist smoothly without changing topology — hence quantization.
Varying strength, masses, generations.
This is the subtle part. In TUFT, coupling strengths and masses are not added by hand — they come from spectral data of topological invariants (Chern-Simons invariants, analytic torsion, knot signatures). Different generations correspond to different interference modes on sub-spheres (S5 for neutrinos, S7 for gluons, etc.). So the “geometry” you’re asking about is really supplied by these spectra: the amount of twist, braiding, and interference fixes the effective coupling and mass.
So the picture is:
Hi — I think I may see where the confusion is coming from.
R vs. R2.
Yes, the real line R and the plane R2 both have the same cardinality (they’re both uncountably infinite). That’s why you can “zipper” the decimals of two real numbers into one — Cantor showed this over 100 years ago. But this is a set-theoretic fact about cardinalities. Geometry/topology adds more structure: in R2 you have two independent coordinates, continuity, smoothness, and so on. That’s what distinguishes “line-like” from “surface-like.”
Smoothness.
When the paper says the real line or plane is “smooth,” it means they are modeled as smooth manifolds. That’s an axiom: we assume differentiable structure so calculus works. This does not follow from cardinality, but from declaring that we want a structure where limits, derivatives, and integrals are well-defined.
“Paradoxes.”
The zipper trick shows that cardinality alone is not enough to capture geometry. That’s not a paradox but a reminder: topology and smooth structure are extra data. A line and a plane are homeomorphic only in the trivial set-theoretic sense of having the same size; they are not homeomorphic or diffeomorphic as manifolds. Structural theorems (like invariance of domain) guarantee that R and R2 cannot be smoothly or continuously reshaped into each other.
Higher spaces.
Spheres, projective planes, etc. are exactly where topology becomes essential. You can’t reduce everything to “just the same number of points.” Instead, you classify spaces by their topological invariants (homotopy groups, cohomology classes, Chern numbers, etc.). That’s the level TUFT is working at.
So short answer: yes, mathematicians know that sets alone blur lines and surfaces. That’s why geometry, topology, and smooth structure are added. Model theory is one framework for thinking about axioms and paradoxes, but in physics we mostly rely on manifold theory and topology to avoid those pathologies.
@Lorraine Ford = Perhaps he speaks a second language or has a neurodivergence but I think I know what he was trying to ask
@David Chester
Hey Chess!
"Did you just use the Higgs vev to find R, and then use R to claim that the Higgs vev was derived? In other words, you could have solved for any R to allow for any value of the Higgs vev, correct?"
Incorrect
In my TUFT construction, the Higgs vacuum expectation value (v ≈ 246 GeV) is obtained from spectral/topological invariants of the bundle:
Chern–Simons invariants, knot signatures, analytic torsion, and interference radii on the relevant fiber/sphere.
These invariants give rise to eigenvalue conditions that directly fix the electroweak scale.
This calculation uses only internal topological data, not the fiber radius R.
The VEV is pinned by the mode structure of the bundle and does not need R to be defined.
Some of these other questions I believe we have addressed before to at least some degree and I am currently editing the paper for publication, but I appreciated your doggedness and I will return to the discussion by the weekend
@"Symbolik Thank you for these questions. I find these helpful, and they are similar to questions from reviewer(s) which I am addressign currently. I will return to the forum later.
Singularities in particular are eliminated under my theory.
Thanks everyone for your detailed / interesting / exciting questions. I will attempt to answer as fully as possible over the next three weeks. I will return to the discussion this weekend for a bit. Right now I am in the middle of 1-week deadline to address reviewer questions and edit for publication.
Zachory It is dynamically derived in the Lagrangian/Equations of motion section if I recall, but I explained the deriation sufficiently where I first introduced it but perhaps not with as great a clarity as I intended to impart. I will return and flesh this out more carefully.
@Jenny Lorraine Nielsen , hello, congratulations for the article!
I also pursue models of particles as topological excitations - since 2009, in 2012 had FQxI essay, since 2021 finally quantitatively combining Landau-de Gennes superfluid liquid crystal-like field with Skyrme-like kinetic term to get e.g. electromagnetism for quantized topological charges (updated https://arxiv.org/pdf/2108.07896 , fresh conference talk ).
String hadronization seems the clearest way - they assume in LHC collision there is formed quark string, and it decays into particles ... this quark string nonperturbatively is modeled as topological vortex, so we just need to find the correspondence - between what topological vortex can decay into, and what they observe in LHC collisions.
The big question is distinguishing fundamental from effective e.g. symmetry groups - living in 4D, the basic symmetry is SO(1,3) Lorentz group of rotations and boosts - field rather has to transform with these fundamental symmetries, and most used can be seen this way (below), but you are using much higher symmetries - do you see them as fundamental or effective?
Jenny Lorraine Nielsen
No excuses. I encountered this individual a few years ago, on FQxI. So, I know that what he says IS drivel.
Jenny Lorraine Nielsen Congrats on your paper , it is a beautiful and general work. Even though I approach things with a different logic through the spherical topological geometric algebras I invented for my theory of spherisation and quantum spheres, I appreciate your contribution.
I believe we cannot truly use the name TOE (Theory of Everything), because there are deep limitations in philosophy, physics, and mathematics. To be frank, I think these limitations will remain even if humanity survives and researches in physics and mathematics for another 10,000 years.
Spacetime is of course important, but maybe ,and I insist maybe , we are in a kind of philosophical prison, due to the way General Relativity (GR) has been considered like a primary essence, especially with the Einstein Field Equations (EFE) and correlations with Quantum Field Theory (QFT). GR and QFT indeed work very well with our measurements and observations, but the real issue for me lies in their philosophical origin and if we have deeper logics hidden and parameters.
When Einstein developed his wonderful theories of relativity, many scientists exclaimed, “Wow, he has understood the universe ,even, in some way, God by considering light as the primary essence.” After that, scientists worked with geometric algebras such as Hopf and Lie......, or developed geometrodynamics with points (like Wheeler), or strings and branes from Witten. And so today, most people view the Planck scale as a framework of points or 1D strings, connected by a 1D cosmic field of GR.
But maybe this is a mistake , focusing only on this single path of fractalisation and extrapolation of dimensions. The same applies to information: whether one calls it God or a mathematical accident, most people interpret it through this “light-based” perspective.
For me, the problem is philosophical , it concerns the notion of primary essence, the fundamental objects, and the true origin of the universe.
That being said, I really liked how you attempt to unify gravity with the other forces without relying on a metric, but rather by reducing GR in 4D. Congrats again , it’s a beautiful idea, Regards
