### The strand conjecture provides a simple explanation for the three gauge groups in nature – and for the absence of any other gauge group.

● How strands lead to gauge symmetry

● What is quantum field theory?

● Testable predictions of
strand gauge theory

● Bibliography

### Summary: gauge theory from strands

Strands allow to derive, from their single fundamental principle, the
three observed gauge theories. More precisely,
strands provide a microscopic model for the three gauge groups U(1),
broken SU(2), and SU(3):
They are due to the three Reidemeister moves.
Strands do not allow any other gauge group.
The strand explanation is *unique:*
all questions about quantum field theory are answered.

### How strands lead to gauge symmetry

In nature, gauge symmetry is due to the freedom to define particle phase. In the tangle model of particles, gauge symmetry is due to the same freedom. Particle phase is defined with the help of strand crossings. Every crossing has the same properties that particle states, i.e., wave functions, also have.

In nature, only three gauge symmetries are observed: U(1) for electrodynamics,
broken SU(2) for the weak interaction, and SU(3) for the strong interaction.
In the tangle model of particles, gauge symmetry is due to strand deformation in the particle core.
Deformations can be classified; this is done by the so-called Reidemeister moves.
The main discovery is:
*Each Reidemeister move corresponds to a gauge group.*

The first Reidemeister group generates U(1), the second SU(2), and the third SU(3). Because there are only three Reidemeister moves, there are only three gauge groups. This connection solves all the questions about gauge theories. Strands imply that there is no other gauge group, no grand unification and no supersymmetry.

### What is quantum field theory?

(This section is taken from the preprint on QCD.)

In the strand conjecture, a *quantum field* is a loose, fluctuating tangle that is made of strands with Planck radius.

The fluctuations of the strand crossings, averaged over time, produce probability densities. The tangle topology fixes the particle type and its quantum numbers. The tangle model allows producing extended, continuous distributions, i.e., fields, while also allowing the counting of discrete particles. The tangle model automatically yields indistinguishable, identical particles. The tangle model reproduces spin and statistics, as well as their connection.

The tangle model implies that particles are countable and localized excitations of the (untangled) vacuum: the excitation is the tangling. The (rational) tangle model reproduces particle creation by tangling, particle annihilation by untangling, particle absorption by tangle combination and particle emission by tangle separation. Vacuum excitations lead both to particles and to antiparticles. The (rational) tangle model also implies that particles can transform into each other: different tangles can be combined or single tangle can be separated into two tangles.

The tangle model implies that interactions are *deformations* of tangles.
The tangle model implies that interactions are local - within Planck dimensions.
The tangle model implies that the interaction spectrum is limited, by the Reidemeister moves, to the three known gauge groups of the standard model.
The tangle model implies that the weak interaction violates parity, breaks SU(2), and violates CP invariance, in contrast to the electromagnetic and the strong interaction.
The tangle model implies that fermions mix, described by unitary mixing matrices.
The tangle model implies that couplings are unique and run with four-momentum.

The tangle model implies that perturbation expansions are due to more complex tangles arising at small scales. The tangle model implies the same perturbation expansion as conventional quantum field theory.

The tangle model implies that quantum fields have a Lagrangian and follow the principle of least action. (This eliminates quantum field theories without Lagrangians.) The tangle model implies that couplings are weak. The tangle model implies that the standard model is renormalizable: tangles allow at most quadruple vertices. The tangle model implies that quantum fields have an (unusual) strong coupling regime - in the tangle cores. The tangle model implies that quantum fields have an approximate duality between strong and weak coupling - but not an exact one. The tangle model implies that quantum fields have topological aspects - but are not topological quantum field theories. The tangle model implies that space is continuous, and not non-cummutative or fermionic. The tangle model of elementary particles is free of anomalies, because the standard model is. The tangle model provides the desired argument explaining why: the lack of anomalies is due to the topology of the elementary particle tangles and to the particle spectrum resulting from tangle classification.

The tangle model implies that there is natural cut-off at the Planck scale. The tangle model implies that there is a well-defined continuum limit - within Planck dimensions. The tangle model also implies that all observables are local - within Planck dimensions. The tangle model implies that observables obey axiomatic quantum field theory - within Planck dimensions and limits.

The tangle model implies that physical space has three dimensions at all scales, that there is only one vacuum state and that flat empty space-time is Lorentz-invariant.

Any counter-example to any of the statements above directly invalidates the strand conjecture.

### Testable predictions of strand gauge theory

Strands provide a simple explanation of the observed gauge groups U(1), broken SU(2), and SU(3).
This explanation is *unique*: there is no other, equally simple explanation in the literature.
In particular, no other explanation eliminates other possible symmetries.

In addition, strands also determine the particle spectrum, the fundamental constants, and general relativity.

Additional gauge groups, additional dimensions, additional particles, additional interactions, additional symmetries - be they local, global, discrete, supersymmetric, or non-commutative - and additional energy scales are all not possible in nature. Above all, values for the fundamental constants that differ from the observed ones are not possible. In other words, the tangle model does not allow generalizations. This feature of a quantum field theory is unusual, but it is required and expected from any unified model.

All predictions can be summarized in a single statement: there is no physics whatsoever beyond the standard model with massive Dirac neutrinos and PMNS mixing and beyond general relativity.

In science, every statement must be checked continuously, again and again. This is ongoing. A sweeping statement like "strands explain gauge theory and quantum field theory, and allow no modification" must be checked with particular care. If you have a potential counterargument or notice a missing issue, just send a note.

More detailed and specific predictions and bets have been formulated here. Finding any single observation falsifying the strand conjecture or the standard model, or just finding an alternative, correct and inequivalent description of gauge theory – or of nature – wins the bet.

### Bibliography

An exploration of QCD is the preprint C. Schiller, Testing a conjecture on quantum chromodynamics.

*

An exploration of QED is the preprint C. Schiller, Testing a conjecture on quantum electrodynamics.

*

A dedicated discussion of the strand description of the standard model was published as C. Schiller, Testing a conjecture on the origin
of the standard model, *European Physical Journal Plus*
**136** (2021) 79. Download it at
doi.org/10.1140/epjp/s13360-020-01046-8.
Read the published paper online for free
at rdcu.be/cdwSI.

Download the preprint here.

*

The first published paper on the strand model was C. Schiller, A conjecture on deducing
general relativity and the standard model with its fundamental constants from
rational
tangles of strands, *Physics of Particles and Nuclei*
**50** (2019) 259–299. Download the published paper at
dx.doi.org/10.1134/S1063779619030055. Read the published paper online for free at rdcu.be/cdCK7.

Download the
preprint here, with films.

*

The first text that explained the relation between gauge groups and strands, in 2009, is available from arxiv as https://arxiv.org/abs/0905.3905.