AbstractQuantum theory has found that elementary particles in addition to the classic field quantity have also quantum-mechanical degree of freedom. This research paper defines another hypothetical intrinsic degree of freedom which has a topological nature. A topological quantum field theory is constructed to this hypothetical degree of freedom.
A well-known topological quantum field theory is the Chern-Simons theory which is strongly related to knot theory (Chern et al. 1974). This theory is applied in various disciplines of theoretical physics. The governing field of the theory is the non-abelian 1-form geometric connection where the action of the Chern-Simons theory does not change when it is varied by . Therefore the field theory is topological. Observables of this theory are given by knot invariants. Chern-Simons theory is a Schwarz-type topological quantum field theory in which the whole action is independent on variations in geometric quantities. There were postulated a couple of other topological quantum field theories in literature (Atiyah 1989).
In physics, the occurrence of topological defects are also well-known. As an example, ordered media can have topological defects (Mermin 1979). Topological defects can affect electromagnetic interactions taking place in a physical system. Electromagnetic systems with topological defects are also studied in research literature (Bakke et al. 2010).
This research paper shows how it is possible to generalize the concept of topological defects to elementary particles. Since quantum physics has found out that elementary particles have properties that are not predicted by classical physics
(e.g. the spin of a particle) it can be assumed that some other microscopic properties of particles are present but not predicted yet. The main purpose of this paper is to show that charged elementary particles like electrons can possess additional internal degree of freedom. This is performed by regarding a topological quantum field theory which is able to take topological defects into account. Primarily, particles with electric charge are described by Quantum electrodynamics. Quantum electrodynamics is a physical theory with a very high agreement with experiments. However, there can be a difference between the real behavior of charged particles and the predictions of Quantum electrodynamics. Some more detailed experimental tests for Quantum electrodynamics are the measurement of the anomalous dipole moment of the muon (Hagiwara et al. 2007).
For the derivation of a quantum field theory which includes topological corrections to ordinary quantum electrodynamics a Witten-type topological quantum field theory is proposed (Witten 1988). The basic quantum field is assumed as a dipole field strength tensor that arises from topological defects. This field is regarded as the geometric quantity of the theory. An additional dipole field will generate a proper generalization of the electromagnetic field strength tensor in quantum electrodynamics. It is shown, how quantum observables will be independent on the dipole field strength tensor. This ensures that the quantum field theory is a topological quantum field theory.
Witten-type topological quantum field theories are based on cohomology theories. The action of such theories must contain a symmetry. More precisely, there must exist a differential operator such that . This differential operator is similar to a Lie derivative and must satisfy the exactness condition
The theory treated in this paper is assumed to be a 4-dimensional theory like ordinary quantum electrodynamics. It is assumed that the operator is the Čech coboundary map. Assuming that geometric fields are defined on a set with arbitrary sets and the condition that is a point in spacetime. Then it is easy to compute the action of the Čech coboundary operator on a function :
Here, the hat denotes that the set is omitted. It is easy to show that the definition (2) satisfies the exactness condition (1). The number of intersecting sets where the intersection of these sets generates the spacetime point can be chosen arbitrary. A simple case is given by the choice . Let be a 2-form field which is the dipole field strength tensor of the charged elementary particle. Because this field is induced by hypothetical topological defects in the elementary particle, this field must be the geometrical quantity of the action. When assuming that the generalized electromagnetic field strength tensor is given by
with the electromagnetic 1-form gauge connection , the field can be interpreted as the intrinsic curvature. In the model treated in this paper quantum electrodynamics is replaced by the generalized field strength tensor (3) where the field of the intrinsic degree of freedom induces additional topological interactions. The fields are the observables of the topological quantum field theory. Therefore, must lie in the cohomology classes of the Čech cohomology, i.e. but with an arbitrary 2-form field .
A suitable action for the generalized quantum electrodynamics has the form:
The field is the fermion field. Assuming that and always satisfying the Čech cocycle condition , the action of on the first term of (4) vanishes. Considering the action functional existing on the spacetime manifold
then it can be easily shown that if it holds for all .
When the auxiliary condition
is imposed, it is straightforward to show that the only tensor invariant of the antisymmetric tensor that is not vanishing is given by .
To show that above assumptions construct a topological quantum field theory, the action (5) must be varied by the field . If all quantum fields vanish on the boundary of it holds for arbitrary 4-form field . For the variation operator it holds the functional derivative rule . From
and (6) it follows .
The condition (7) is also a condition for a Witten-type topological quantum field theory. It ensures that the every observable that lies in a Čech cohomology class has an expectation value
is independent on variations in the geometrical quantity . If the auxiliary field is introduced which is also involved in the functional integration, i.e. , the action can be extended by a term that describes the auxiliary condition in the following manner:
The action in the general form (9) describes the complete quantum field theory.
This generalization of quantum electrodynamics by topological quantum fields is a model for describing a hypothetical intrinsic dipole moment of a charged elementary particle. Above considerations show that the topological term of the action is similar to the abelian Chern-Simons theory. The photon field strength tensor of quantum electrodynamics is coupled to an additional dipole moment which is of purely topological nature.
Chern, S.- S. & Simons, J. "Characteristic forms and geometric invariants". Annals of Mathematics, 1974, 99 (1): 48-69. doi: 10.2307/1971013
Atiyah, Michael. "Topological quantum field theories". Publications des Mathématiques de l'IHÉS, 1989, 68 (68): 175-186. doi: 10.1007/BF02698547
Mermin, N. D. "The topological theory of defects in ordered media". Reviews of Modern Physics , 1979, 51 (3): 591.
Bakke, K. & Ribeiro L.R. & Furtado C. "Landau quantization for an induced electric dipole in the presence of topological defects". Central European Journal of Physics, 2010, 8 (6): 893-899. doi: 10.2478/s11534-010-0006-z
K. Hagiwara & A.D. Martin & Daisuke Nomura & T. Teubner. "Improved predictions for g−2 of the muon and αQED(MZ²)". Phys.Lett. B, 2007, 649: 173-179. doi: 10.1016/j.physletb.2007.04.012
Witten, E. "Topological quantum field theory", Communications in Mathematical Physics, 1988, 117 (3): 353–386. doi: 10.1007/BF01223371
Showing 10 Reviews
The individual topics that are mentioned are
certainly interesting, but they appear a bit mixed up by the author. I
am not sure what he means by a dipole field strength tensor. Perhaps a
polarization tensor? Adding a (non-closed) 2-form B-field to the
electromagnetic tensor F can be useful to describe magnetic charges
Additional Information for better understanding of the paper:
For computation of scattering amplitudes one can define
B = gB'+ \phi \delta B
where \phi is the 0-form indicator function defined on the support of B and g is a coupling constant. When applying the Operator \delta to B one obtains (due to \delta B' = 0):
\delta B = \delta(gB'+\phi \delta B) = g \delta B' + (\delta \phi) \delta B + \phi \delta^2 B =
(\delta \phi) \delta B.
Note that since \delta \phi is the indicator function defined on the support of the Čech coboundary and therefore on the Support of \delta B, it holds also (\delta \phi) \delta B = \delta B. Hence, above decomposition is possible.
Now the Haar measure d[B] can be decomposed in a cohomological part and in the non-exact part \phi \delta B , i.e. \int d[B]= \int d[B'] \int d[\phi \delta B]. For abbreviation it is set
W = \phi \delta B = (\delta \phi) \delta B
since \phi and \delta \phi have the same support as \delta B. The partition function can be written as:
= \int d[\lambda] \int d[B'] \int [W] O exp(igB' \wedge W + i(1+\lambda)W \wedge W). (*)
Physical observables are given by products of B'. In this case the Integration over B' in partition function (*) can be performed such that delta distributions and derivatives of delta distributions in argument W occur. Finally, it can be integrated over W and \lambda which gives a number. It is important that Integration over \lambda is performed between -L and +L with L \mapsto \infty. With this regularization, the infinities can be absorbed in the coupling constant g, i.e.
g' = gL.
Now the coupling constant of Topological Dipole Field Theory is given by g'. For the computation of expectation values the division by the normalization factor
N = \int d[B'] \int d[W] \int d[\lambda] exp(igB' \wedge W + i(1+\lambda)W \wedge W) =
\int d[W] \int d[\lambda] (2 \pi)^n \delta(gW) exp(i(1+\lambda)W \wedge W) =
\int d[\lambda] (2 \pi g^(-1))^n.
with n \mapsto \infty has to be executed. Noting that \int d[\lambda] \lambda = 0 and \int d[\lambda] \lambda^2 \neq 0 it is easy to show that the first nontrivial physical expectation value that does not vanish is an expectation value over a polynomial in B which has at least the
4th degree. This expectation value is of order g'^(-4); hence if g'^(-1) is small then the correction of Topological Dipole Field theory to Quantum Electrodynamics is also small.
The differential Operator \delta maps to the Čech coboundary that must lie in an infinitesimal neighborhood of the spacetime Point to act as a differential operator.
Good topic , wish you all the best
An articulate matter indeed. However it is of slight confusion for me about the dipole field strength tensor. Overall a genuinely verdant calculation with standard tools and very appropriate use of resources and references. Introduction is way more lucid and makes it an easier approach.
Its a very interesting research topic. I like your idea and theory. It looks like you give a good explanation to your figures about your theory. I love subjects that deal with Topological and especially Cosmology.
I have read other research papers on the internet. I have notice some researchers use subtitles and diagrams in their research paper. You can try to use that, Its only a suggestion.
Incredible work ever I seen in our young generation, and also my commment is on equation (1) and (2), where (1) is the exactness condition. I cant understand here, but physics and idea is really good!
very good topic
Nothing is actually acheived, despite the author claiming so. There is no connection made to the existing tested models of physics. The author uses sophisticated mathematical terminology to hide the fact that nothing is being said. On the note of mathematics, that is also incorrect. Functions/maps are not well-defined; for example, the function f acts on a set or a point depending on context. This is another article which any self-respecting editor would reject immediately, without wasting time for reviewers. A significant amount of work is required if the author would like to see this received by anyone in the physics community.
I have the impression this paper is serious. Not only the exactness condition is fulfilled, also the action in the general form describes the complete quantum field theory.
This theory is a vast and immane success. You can do anything. The only limit, is yourself!
The author has written an interesting Topic. Calculation steps are Logically consistent and on a high mathematical Level. At the end of the paper a more plausible equation (without usin cohomology theory) is provided. An interesting fact is that the theory does not depend on mathematical Details of the underlying cohomology theory which makes TDFT a very interesting theory.
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