arXiv subjects

Johan Hansson

Publications and source records attributed to Johan Hansson.

At least 19 recordsLinked to original sources

arXiv2023

The magical "Born Rule" & quantum "measurement": Implications for Physics

I. The arena of quantum mechanics and quantum field theory is the abstract, unobserved and unobservable, M-dimensional formal Hilbert space [not equal to] spacetime. II. The arena of observations and, more generally, of all events (i.e. everything) in the real physical world, is the classical 4-dimensional physical spacetime. III. The "Born Rule" is the random process "magically" transforming I. into II. Wavefunctions are superposed and entangled only in the abstract space I., never in spacetime II. Attempted formulations of quantum theory directly in real physical spacetime actually constitute examples of "locally real" theories, as defined by Clauser & Horne, and are therefore already empirically refuted by the numerous tests of Bell's theorem in real, controlled experiments in laboratories here on Earth. Observed quantum entities, i.e. events, are never superposed or entangled as they: 1) Exclusively "live" (manifest) in real physical spacetime, 2) Are not described by entangled wavefunctions after "measurement", effectuated by III. When separated and treated correctly in this way, a number of fundamental problems and "paradoxes" of quantum theory vs. relativity (i.e. spacetime) simply vanish, such as the black hole information paradox, infinite zero-point energy of quantum field theory and quantization of general relativity.

physics.gen-ph↗

arXiv2018

Nonlinear Effects of Gravity in Cosmology

We consider some nonlinear effects of gravity in cosmology. Possible physically interesting consequences include: non-requirement of dark matter and dark energy, asymmetric gravitational matter-creation, emergent homogeneity/isotropy & asymptotic flatness, resolution of "cosmic coincidence" Omega_m \sim Omega_lambda, effective cutoff of gravitational interaction at the scale of cosmic voids.

physics.gen-ph↗

arXiv2017

Testing Quantum Gravity

The search for a theory of quantum gravity is the most fundamental problem in all of theoretical physics, but there are as yet no experimental results at all to guide this endeavor. What seems to be needed is a pragmatic way to test if gravitation really occurs between quantum objects or not. In this article we suggest such a potential way out of this deadlock, utilizing macroscopic quantum systems; superfluid helium, gaseous Bose-Einstein condensates and "macroscopic" molecules. It turns out that true quantum gravity effects - here defined as observable gravitational interactions between truly quantum objects - could and should be seen (if they occur in nature) using existing technology. A falsification of the low-energy limit, in the accessible weak-field regime, would also falsify the full theory of quantum gravity, making it enter the realm of testable, potentially falsifiable theories, i.e. becoming real physics after almost a century of pure theorizing. If weak-field gravity between quantum objects is shown to be absent (in the regime where the approximation should apply), we know that gravity then is a strictly classical phenomenon absent at the quantum level.

gr-qc↗

arXiv2014

Physical Origin of Elementary Particle Masses

In contemporary particle physics, the masses of fundamental particles are incalculable constants, being supplied by experimental values. Inspired by observation of the empirical particle mass spectrum, and their corresponding physical interaction couplings, we propose that the masses of elementary particles arise solely due to the self-interaction of the fields associated with the charges of a particle. A first application of this idea is seen to yield correct order of magnitude predictions for neutrinos, charged leptons and quarks. We then discuss more ambitious models, where also different generations may arise from \textit{e.g.} self-organizing bifurcations due to the underlying non-linear dynamics, with the coupling strength acting as "non-linearity" parameter. If the model is extended to include gauge bosons, the photon is automatically the only fundamental particle to remain massless as it has no charges. It results that gluons have an effective range $\sim 1$fm, physically explaining why QCD has finite reach.

physics.gen-ph↗

arXiv2014

"Quantum machine" to solve quantum "measurement problem"?

Recently a study of the first superposed mechanical quantum object ("machine") visible to the naked eye was published. However, as we show, it turns out that if the object would actually be observed, i.e. would interact with an optical photon, the quantum behavior should vanish. This, the actual observation, has long been suspected in many interpretations of quantum mechanics to be what makes the transition quantum $\rightarrow$ classical, but so far it has not been available for direct experimental study in a mechanical system. We show how any interaction, even a purely quantum one, of sufficient strength can constitute a physical "measurement" - essentially the emergence of an effectively classical object - active observation thus being a sufficient but not necessary criterion. So it seems we have in this case of the "quantum machine" a unique possibility to study, and possibly solve, the long-standing "measurement problem" of quantum mechanics.

physics.gen-ph↗

arXiv2013

Pulsars: Cosmic Permanent 'Neutromagnets'?

We argue that pulsars may be spin-polarized neutron stars, i.e. cosmic permanent magnets. This would simply explain several observational facts about pulsars, including the 'beacon effect' itself i.e. the static/stable misalignment of rotational and magnetic axes, the extreme temporal stability of the pulses and the existence of an upper limit for the magnetic field strength - coinciding with the one observed in "magnetars". Although our model admittedly is speculative, this latter fact seems to us unlikely to be pure coincidence.

astro-ph.HE↗

arXiv2012

On the Origin of Elementary Particle Masses

The oldest enigma in fundamental particle physics is: Where do the observed masses of elementary particles come from? Inspired by observation of the empirical particle mass spectrum we propose that the masses of elementary particles arise solely due to the self-interaction of the fields associated with a particle. We thus assume that the mass is proportional to the strength of the interaction of the field with itself. A simple application of this idea to the fermions is seen to yield a mass for the neutrino in line with constraints from direct experimental upper limits and correct order of magnitude predictions of mass separations between neutrinos, charged leptons and quarks. The neutrino interacts only through the weak force, hence becomes light. The electron interacts also via electromagnetism and accordingly becomes heavier. The quarks also have strong interactions and become heavy. The photon is the only fundamental particle to remain massless, as it is chargeless. Gluons gain mass comparable to quarks, or slightly larger due to a somewhat larger color charge. Including particles outside the standard model proper, gravitons are not exactly massless, but very light due to their very weak self-interaction. Some immediate and physically interesting consequences arise: i) Gluons have an effective range $\sim 1$fm, physically explaining why QCD has finite reach ii) Gravity has an effective range $\sim 100$ Mpc coinciding with the largest known structures; the cosmic voids iii) Gravitational waves undergo dispersion even in vacuum, and have all five polarizations (not just the two of $m=0$), which might explain why they have not yet been detected.

physics.gen-ph↗

arXiv2011

Reality or Locality? - Proposed test to decide \textit{how} Nature breaks Bell's inequality

Bell's theorem, and its experimental tests, has shown that the two premises for Bell's inequality - locality and objective reality - cannot both hold in nature, as Bell's inequality is broken. A simple test is proposed, which for the first time may decide which alternative nature actually prefers on the fundamental, quantum level. If each microscopic event is truly random (e.g. as assumed in orthodox quantum mechanics) objective reality is not valid, whereas if each event is described by an unknown but deterministic mechanism ("hidden variables") locality is not valid. This may be analyzed and decided by the well-known reconstruction method of Ruelle and Takens; in the former case no structure should be discerned, in the latter a reconstructed structure should be visible. This could in principle be tested by comparing individual "hits" in a double slit experiment, but in practice a single fluorescent atom, and its (seemingly random) temporal switching between active/inactive states would possibly be better/more practical, easier to set up, observe and analyze. However, only imagination limits the list of possible experimental setups.

quant-ph↗

arXiv2010

Nonlinear gauge interactions: a possible solution to the "measurement problem" in quantum mechanics

Two fundamental, and unsolved problems in physics are: i) the resolution of the "measurement problem" in quantum mechanics ii) the quantization of strongly nonlinear (nonabelian) gauge theories. The aim of this paper is to suggest that these two problems might be linked, and that a mutual, simultaneous solution to both might exist. We propose that the mechanism responsible for the "collapse of the wave function" in quantum mechanics is the nonlinearities already present in the theory via nonabelian gauge interactions. Unlike all other models of spontaneous collapse, our proposal is, to the best of our knowledge, the only one which does not introduce any new elements into the theory. A possible experimental test of the model would be to compare the coherence lengths - here defined as the distance over which quantum mechanical superposition is still valid - for, \textit{e.g}, electrons and photons in a double-slit experiment. The electrons should have a finite coherence length, while photons should have a much longer coherence length (in principle infinite, if gravity - a very weak effect indeed unless we approach the Planck scale - is ignored).

quant-ph↗

arXiv2009

Aspects of nonrelativistic quantum gravity

A nonrelativistic approach to quantum gravity is studied. At least for weak gravitational fields it should be a valid approximation. Such an approach can be used to point out problems and prospects inherent in a more exact theory of quantum gravity, yet to be discovered. Nonrelativistic quantum gravity, e.g., shows promise for prohibiting black holes altogether (which would eliminate singularities and also solve the black hole information paradox), gives gravitational radiation even in the spherically symmetric case, and supports non-locality (quantum entanglement). Its predictions should also be testable at length scales well above the "Planck scale", by high-precision experiments feasible with existing technology.

gr-qc↗

arXiv2009

Inhomogeneous structure formation may alleviate need for accelerating universe

When taking the real, inhomogeneous and anisotropic matter distribution in the semi-local universe into account, there may be no need to postulate an accelerating expansion of the universe despite recent type Ia supernova data. Local curvatures must be integrated (over all space) to obtain the global curvature of the universe, which seems to be very close to zero from cosmic microwave background data. As gravitational structure formation creates bound regions of positive curvature, the regions in between become negatively curved in order to comply with a vanishing global curvature. The actual dynamics of the universe is altered due to the self-induced inhomogeneities, again more prominently so as structure formation progresses. Furthermore, this negative curvature will increase as a function of time as structure formation proceeds, which mimics the effect of "dark energy" with negative pressure. Hence, the "acceleration" may be merely a mirage. We make a qualitative and semi-quantitative analysis, using newtonian gravity corrected for special relativistic effects, which works surprisingly well, to corroborate and illustrate/visualize these statements. This article may be seen as a plea to start taking seriously the observed inhomogeneous distribution and the nonlinearities of nonperturbative general relativity, and their impact on the dynamics and behavior of the cosmos.

physics.gen-ph↗

arXiv2006

Newtonian Quantum Gravity

A Newtonian approach to quantum gravity is studied. At least for weak gravitational fields it should be a valid approximation. Such an approach could be used to point out problems and prospects inherent in a more exact theory of quantum gravity, yet to be discovered. Newtonian quantum gravity, e.g., shows promise for prohibiting black holes altogether (which would eliminate singularities and also solve the black hole information paradox), breaks the equivalence principle of general relativity, and supports non-local interactions (quantum entanglement). Its predictions should also be testable at length scales well above the "Planck scale", by high-precision experiments feasible even with existing technology. As an illustration of the theory, it turns out that the solar system, superficially, perfectly well can be described as a quantum gravitational system, provided that the $l$ quantum number has its maximum value, $n-1$. This results exactly in Kepler's third law. If also the $m$ quantum number has its maximum value ($\pm l$) the probability density has a very narrow torus-like form, centered around the classical planetary orbits. However, as the probability density is independent of the azimuthal angle $ϕ$ there is, from quantum gravity arguments, no reason for planets to be located in any unique place along the orbit (or even \textit{in} an orbit for $m \neq \pm l$). This is, in essence, a reflection of the "measurement problem" inherent in all quantum descriptions.

gr-qc↗

arXiv2006

A hierarchy of cosmic compact objects - without black holes

We make the case for the existence of a, hitherto unknown and unobserved, hierarchy of ever more compact cosmic objects in the universe. This hypothesis is based on i) the assumption of "elementary" particle sub-constituents on several levels below the presently known, inspired by Glashow's "blooming desert", ii) the existence of nearly scale-invariant density fluctuations in the early universe, e.g. as predicted by inflationary models, iii) our own previous theoretical work showing that a class of objects considerably more compact than previously thought possible in astrophysics can exist. We also give several independent arguments strongly pointing towards the non-existence of black holes. Some brief suggestions on observational signals due to the hierarchy, both in collected astronomical data and in possible future observations, concludes the paper.

astro-ph↗

arXiv2003

Comment on "Measurement of quantum states of neutrons in the Earth's gravitational field"

In the paper by V.V. Nesvizhevsky et al., Phys. Rev. D 67, 102002 (2003), it is argued that the lowest quantum state of neutrons in the Earth's gravitational field has been experimentally identified. While this is most likely correct, it is imperative to investigate all alternative explanations of the result in order to close all loopholes, as it is the first experiment ever claimed to have observed gravitational quantum states. Here we show that geometrical effects in the experimental setup can mimic the results attributed to gravity. Modifications of the experimental setup to close these possible loopholes are suggested.

quant-ph↗

arXiv2003

The "proton spin crisis" - a quantum query

The "proton spin crisis" was introduced in the late 1980s, when the EMC-experiment revealed that little or nothing of a proton's spin seemed to be carried by its quarks. The main objective of this paper is to point out that it is wrong to assume that the proton spin, measured by completely different experimental setups, should be the same in all circumstances.

hep-ph↗

arXiv2003

Reply to comment on ``A simple explanation of the non-appearance of physical gluons and quarks"

This is the reply to a comment by Andreas Aste [hep-th/0302103] on a previous article of mine in Can.J.Phys. The counter-arguments used by Aste utilize a mathematical limit without physical meaning. We still contend that in QCD, the particles ``gluons'' and ``quarks'' are merely artifacts of an approximation method (the perturbative expansion) and are simply absent in the exact theory.

hep-ph↗

arXiv2002

A simple explanation of the non-appearance of physical gluons and quarks

We show that the non-appearance of gluons and quarks as physical particles is a rigorous and automatic result of the full, i.e. nonperturbative, nonabelian nature of the color interaction in quantum chromodynamics. This makes it in general impossible to describe the color field as a collection of elementary quanta (gluons). Neither can a quark be an elementary quantum of the quark field, as the color field of which it is the source is itself a source, making isolated noninteracting quarks, crucial for a physical particle interpretation, impossible. In geometrical language, the impossibility of quarks and gluons as physical elementary particles arises due to the fact that the color Yang-Mills space does not have a constant trivial curvature. In QCD, the particles ``gluons'' and ``quarks'' are merely artifacts of an approximation method (the perturbative expansion) and are simply absent in the exact theory. This also coincides with the empirical, experimental evidence.

hep-ph↗

arXiv2002

Preon Trinity - A Schematic Model of Leptons, Quarks and Heavy Vector Bosons

Quarks, leptons and heavy vector bosons are suggested to be composed of stable spin-1/2 preons, existing in three flavours, combined according to simple rules. Straightforward consequences of an SU(3) preon-flavour symmetry are the conservation of three lepton numbers, oscillations and decays between some neutrinos, and the mixing of the d and s quarks, as well as of the vector fields W^0 and B^0. We find a relation between the Cabibbo and Weinberg mixing angles, and predict new (heavy) leptons, quarks and vector bosons, some of which might be observable at the Fermilab Tevatron and the future CERN LHC. A heavy neutrino might even be visible in existing data from the CERN LEP facility.

hep-ph↗