QM foundations & nature of time
seminar
relaxed discussions about the foundations
of physics
Tuesdays at 18 Warsaw time
Paweł Błasiak, Jarosław
Duda, contact: jaroslaw.duda@uj.edu.pl, speakers are welcomed


20210126 
Mark
Hadley (Warwick) Time orientability.
What it is and why it is important. I will explain what the orientability of time is, in particular a
space time that is not time orientable. In principle this can explain the
quantum world. It allows topology change in general relativity. I will show
space time structure with net electric charge from the source free Maxwell
equations. And the strange property for spin half arises naturally in
particle models that are not time orientable. I’ll conclude by describing a
definitive test of time non orientability – with a positive result (slides,
video). 
20201229 
Marek
Danielewski (AGH) Foundations of the Quaternion Quantum Mechanics We show that quaternion quantum mechanics has wellfounded
mathematical roots and can be derived from the model of the elastic continuum
by French mathematician Augustin Cauchy, i.e., it can be regarded as
representing the physical reality of elastic continuum. Starting from the
Cauchy theory (classical balance equations for isotropic Cauchyelastic
material) and using the Hamilton quaternion algebra, we present a rigorous
derivation of the quaternion form of the non and relativistic wave equations.
The family of the wave equations and the Poisson equation are a
straightforward consequence of the quaternion representation of the Cauchy
model of the elastic continuum. This is the most general kind of quantum
mechanics possessing the same kind of calculus of assertions as conventional
quantum mechanics. The problem of the Schrödinger equation, where imaginary
‘i’ should emerge, is solved. This interpretation is a serious attempt to
describe the ontology of quantum mechanics, and demonstrates that, besides
Bohmian mechanics, the complete ontological interpretations of quantum theory
exists. The model can be generalized and falsified.
To ensure this theory to be true, we specified problems, allowing exposing
its falsity (article,
slides,
~video). 
20201006 
Dagomir
Kaszlikowski (NUS), Pawel Kurzynski (UAM)
Another take on negative probabilities? We present preliminary studies of
basic informationtheoretic and computational properties of negative binary
probability distribution called nebit: p(0)=1+\delta,
p(1)=\delta. We show an interesting computational model based on
quasistochastic processes between an ordinary bit and nebit. Finally, we
show that some classical information processing protocols can be more
effective with an access to nebits (article) . 
20200929 
Álvaro
García López (URJC) On
an electrodynamic origin of quantum fluctuations We use the Liénard–Wiechert
potential to show that very violent fluctuations are experienced by an electromagnetic
charged extended particle when it is perturbed from its rest state. The
feedback interaction of Coulombian and radiative fields among different
charged parts of the particle makes uniform motion unstable. Then, we show
that radiative fields and radiation reaction produce dissipative and
antidamping effects, triggering a selfoscillation. Finally, we compute the
selfpotential, which in addition to rest and kinetic energy, gives rise to a
new contribution that shares features with the quantum potential. We suggest
that this contribution to selfenergy produces a symmetry breaking of the
Lorentz group, bridging classical electromagnetism and quantum mechanics (article,
slides). 
20200915 
Fritz W. Bopp (Siegen U.) How to Avoid Absolute Determinismin Two Boundary
Quantum Dynamics Arguments for a two
boundary theory are outlined. A quantum statistical effect plays a
central role. Plausible concepts of how in such a theory an approximate
causal macroscopic theory can emerge are presented. A problem with simple
implementations of the two boundary theory is that
effective or real willful decisions can not be added as there is no
consecutive macroscopic time ordering of such effective or real willful
decision points. We present a
somewhat drastic but somehow beautiful way to avoid it (article, slides) 
20200901 
Jarek Duda
(JU) Maximal
Entropy Random Walk: repairing diffusionQM disagreement Considering diffusion or chaos in [0,1] range leads to uniform stationary
probability distribution rho=1. In contrast, QM predicts localized rho~sin^2
there. This disagreement is crucial e.g. for
semiconductors – standard diffusion would predict nearly uniform electron
distribution, allowing them to flow – incorrectly expecting it to be a
conductor. In contrast, QM predicts strong e.g. Anderson
localization preventing conductance. Maximal Entropy Random Walk (MERW) allows to understand and repair this
disagreement  turns out that standard random walk often only approximates
the (Jaynes) principle of maximal entropy, which is crucial for statistical
physics models – MERW is the most random among random walk, thanks of it
leading to stationary probability distribution exactly as quantum ground
state – with localization property. In contrast to standard random walk, MERW
is also scalefree, time symmetric and nonlocal. It also has many other
applications (~160 citations). (Wikipedia,
article,
thesis,
conductance
simulator, video, slides). 
20200818 
Robert Close (Clark College) Classical Wave Mechanics This is an attempt to describe
elementary particles using classical continuum mechanics. First, a wave
equation is derived for infinitesimal shear waves in an elastic solid. Next,
a change of variables is used to describe the waves in terms of classical
spin angular momentum density, which is the field whose curl is equal to
twice the classical momentum density. The secondorder wave equation is then
converted to a firstorder Dirac equation. Plane wave solutions are
presented, and the dynamical operators of relativistic quantum mechanics are
derived. Wave interference gives rise to the Pauli exclusion principle and
electromagnetic potentials. (draft, slides,
videos) 
20200811 
Christopher Halcrow
(Leeds) Nuclei
as Skyrmions In standard models of nuclear
physics, nuclei are described as point particles with spin and isospin
degrees of freedom. The baryon number (the number of protons plus the
number of neutrons) is conserved in nuclear interactions  this fact is
usually put in “by hand”. In contrast, the Skyrme model describes nuclei as
topological solitons. The baryon number is conserved due to a
topological invariant of the theory while spin and isospin appear as
quantised isometries of the system. This talk is in two parts: first, I will
try and convince you that the Skyrme model is a reasonable model of
nuclear physics. It reproduces several known phenomena: nuclear
clustering, isospin symmetry and rotational bands in energy spectra. I
will then show that the Skyrme model is very different than standard
nuclear models: the notion of position breaks down,
the Deuteron is a torus and novel scatterings can take place. These
surprising facts can give new explanations for some nuclear properties. For
instance, the existence of a toroidal Skyrmion explains the attractive
spinorbit force in the nucleonnucleon interaction as shown recently
in arXiv:2007.01304. I will explain this phenomena
assuming no background knowledge of Skyrmions or nuclear physics. (article,
slides) 
20200804 
Krzysztof Pomorski (UC
Dublin) From superfluidity to cosmology and elementary particles (based on
"The
universe in helium droplet" by G. Volovik”) 
20200728 
Jarek Duda (JU) Discussion: are
there experiments proving or disproving time symmetry? Time/CPT symmetry is at heart of many models of physics, like unitary
evolution in quantum mechanics, or Lagrangian formalism we use from classical
mechanics, electromagnetism, up to general relativity and quantum field
theories. However, this symmetry is quite nonintuitive, very difficult to
really accept – mainly due to thermodynamical counterarguments. Let us try to discuss these arguments, especially experimentbased. I
will present some for us to discuss (adding more is welcomed), for example:
Wheeler’s, delayed choice quantum eraser (DCQE), “asking photons where they
have been”, “photonic quantum routers”, Shor algorithm as more sophisticated
DCQE, also: Anderson localization (starting with rho~sin^2 in [0,1]), Born
rule, Bell violation. (slides, video) 
20200721 
Kenneth Wharton (SJSU) Bell's Theorem: Implications and
Misapprehensions Despite the fact that Bell’s Theorem
tells us something profound about our universe, there are still many
misapprehensions about exactly what it means, even among physicists. For example, it is often incorrectly
characterized as disproving hidden variables, or proving actionatadistance. Even experts in quantum foundations are
sometimes unaware of subtleties concerning the role of an “arrow of time” in
Bell’s analysis and the possibilities of using retrocausation to model
quantum entanglement in a locallymediated, spacetimebased framework. This talk will attempt to clarify these and
other issues, detailing an explicit retrocausal model which accounts for
maximally entangled states. (article, slides)

20200714 
Arkadiusz Jadczyk (Toulouse, CNRS) Order
out of chaos. Fractals out of qubits. Theory can predict what happens when several noncommuting observables
are being simultaneously measured. The results of such repetitive measurements are
random and chaotic, but distinct and organized fractal attractors may arise.
We study quantum iterated function systems for a qubit, where measurements
and quantum jumps are implemented by Moebius transformations of the Bloch
sphere. As an example, a quantum fractal resulting from noncommuting
parabolic transformations is discussed in detail. (slides,
book) 
20200707 
Robert Brady (Cambridge) In memoriam: Yves Couder Yves Couder died on 2 April 2019.
He showed how to make droplets of oil bounce on an oil surface, spawning a
renewed interest in the net forces between oscillating systems. Bouncing
droplets are governed by the ordinary equations of Newtonian mechanics, yet
experimentally their motion mimics the known equations of special relativity,
electromagnetism, and quantum mechanics. I will show why this is the case, in
an idealised system where the pumping acceleration can be neglected. I will
then briefly discuss my ongoing research in a related system in superfluid
helium, where pumping is superfluous and the predictions may be tested
against experiment. In order to maintain your
interest, and to pay respect to Yves, I will give an interpretation of his
work which is controversial. If his results had been known 100 years ago,
they would probably have changed the debate, from 1905 to 1922, between
Einstein and Lorentz on how to interpret the equations of special relativity.
(slides) 
20200630 
Łukasz Stępień (PUK) This and that on solitons and some their
applications I am going to talk about solitons.
I will remind brieﬂy their history and some fundamental facts from soliton theory. Next,
I will say about one of the important tools for investigation of soliton
equations: Bogomolny (Bogomol’nyi) equations, called also as Bogomolny
decomposition, and I will present also an example  Bogomolny equations in
the socalled baby BPS Skyrme model. Later I will say about a soliton model
of particle. 
20200623 
Jarek Duda (JU) Topological charge
as electric charge – can we get all particles this way? We can repair Gauss law to return only integer charges (as in nature)
by interpreting EM field as curvature of some e.g.
vector field, this way counting winding number (topological charge) using
GaussBonnet theorem as Gauss law (Faber’s model). I will lightly introduce
it and would like to discuss if we could expand it to a field
which excitations (e.g. topological) agree with the entire particle
physics, could be effectively described by something close to the Standard
Model. Kind of superfuid biaxial nematic: 3 distinguishable axes in every
point (using tensor field instead of molecules) seems quite promising here.
They can form hedgehog configuration with one of 3 axes, getting 3 leptons
(as spatial dimensions), trying to align the second axis for it we cannot do
it due to the hairy ball theorem (no naked charges – leptons need magnetic
dipoles), then baryonlike configurations enforcing some positive charge:
needed to be compensated in neutron (hence it is heavier than proton), charge
is shared in deuteron for binding (leading to observed electric quadrupole
moment). (slides, video) 
20200616 
Manfried Faber (TU Wien) Topological
excitations of a scalar SO(3)theory We discuss a model with only three degrees of freedom in Minkowski
spacetime. This model is related to Dirac monopoles, one can see it as a
generalisation of the SineGordon model from 1D to 3D, or a modification of
the Skyrme model. Starting from a Lagrangian, the intention of the model is
to provide a geometrical description of electromagnetic phenomena. The model
has three topological quantum numbers which can be compared to the properties
of charge, spin and photon number. We discuss stable solitonic solutions and
compare them to the properties of electrons and photons. (slides, article) 
20200609 
Ilan Roth (Berkeley) From Braids
to Knots; Topological features in Solar Magnetic Fields – and beyond… The
generally accepted structure of magnetic fields depicts them as field lines
in R^{3} with curvature, rotation and wiggles, satisfying divB=0.
Their observed configuration allows us to implement the powerful topological
methods, opening a new venue for an interpretation of various solar,
interplanetary and astrophysical phenomena. Direct imaging of the coronal
fields pinpoints to their braiding structure, large solar wind field reversal
(switchback) and intermittent fading of energetic flare ions suggest that
coronal braided field may have been carried by the solar wind. The
interconnection between the mathematical braids and knots is applied to the
topologically nontrivial magnetized structures and their dynamics, from
solar corona and the interplanetary medium to the astrophysical Herbig – Haro
jets. The topological invariants attached to a given knot/braid become the
crucial factor in the evolution and interpretation of the phenomena in space.
The methods involved cover classical as well as analogues of quantum
procedures. The analysis results in conjectures regarding (i) stability of coronal
magnetic loops under large oscillations, (ii) their evolution through
successive emergence/decay of heated magnetic braids, (iii) their morphism
into the solar wind knotty structures and (iv) large scale narrow jets
emitted in starforming regions. These conjectures may contribute
significantly to the understanding of physical processes in the lab and in
solar/astrophysical medium, particularly in the dynamo produced magnetic
structures as observed by Parker Solar Probe. (some
materials: coronal loop,
magnetic
reconnections, article1, article2, book) 
20200602 
Krzysztof Pomorski (UC Dublin) Review of
book "The universe in helium
droplet" by G. Volovik There are fundamental relations between three vast areas of physics:
particle physics, cosmology, and condensed matter physics. The fundamental
links between the first two areas — in other words, between micro and
macroworlds — have been well established. There is a unified system of laws
governing the scales from subatomic particles to the cosmos and this
principle is widely exploited in the description of the physics of the early
universe. This book aims to establish and define the connection of these two
fields with condensed matter physics. According to the modern view,
elementary particles (electrons, neutrinos, quarks, etc.) are excitations of
a more fundamental medium called the quantum vacuum. This is the new ‘aether’
of the 21st century. Electromagnetism, gravity, and the fields transferring
weak and strong interactions all represent different types of the collective
motion of the quantum vacuum. Among the existing condensed matter systems, a
quantum liquid called superfluid 3HeA most closely represents the quantum
vacuum. Its quasiparticles are very similar to the elementary particles,
while the collective modes are analogues of photons and gravitons. The
fundamental laws of physics, such as the laws of relativity (Lorentz
invariance) and gauge invariance, arise when the temperature of the quantum
liquid decreases (slides) 
20200526 
Arkadiusz Jadczyk (Toulouse, CNRS) Time of
arrival in quantum theory While all our knowledge of the outside world is based on observation
of events, the standard quantum theory does not have tools allowing us to
model events arising in real time, as in all our experiments. A typical example
are events in a particle cloud chamber. A simple extension of the quantum
theory is proposed that fixes this serious shortcoming. In particular the new
solution to the problem of time of arrival in quantum theory is presented. It
allows for computer simulation of particle counters and it implies Born's
interpretation (slides) 
20200519 
Radosław Kycia (CUT) Cartan Connection
for Schrodinger equation. The nature of vacuum I will present the Schrodinger equation's factorization into the
(elliptic) background and an (evolutionary) part moving on this background.
It is a slightly generalized picture than in the pilotwave theory. Moreover,
if the Schrodinger equation is interpreted as a continuity equation, then the
Cartan connection appearing in this equation is precisely the background.
Therefore, the equation and the background can be interpreted geometrically.
The vital role in this approach plays the scaling/dilation group of the wave
function. This corresponds to the original idea of Weyl that leads to the
concept of the gauge principle. The
talk is based on arXiv:2004.04622
[mathph] (slides) 
20200512 
Jarek Duda (JU) Hydrodynamical
analogues of some quantum phenomena As our understanding of quantum mechanics might be not satisfactory,
it could be helpful to search and study more accessible analogues of its
phenomena. Hydrodynamics contains many of them, for example of Casimir and
AharonovBohm effect, and many others with the popular waveparticle duality
“walking droplets”: double slit interference, tunneling, many types of orbit
quantization (including double quantization (radius + angular momentum) and
Zeeman effect), path statistics agreeing with wavefunction. Let us look
closer and discuss applicability of these analogues. (article, slides) 
20200505 
Kenneth Wharton (SJSU) How TimeSymmetry
is compatible with the Second Law: A Discussion All fundamental physics
appears to be governed by timesymmetric laws. (Actually, CPTsymmetric, but this detail
is a red herring.) And yet our
observable universe is dominated by timeasymmetric thermodynamic
behavior. There is a simple but still
widelymisunderstood resolution of this apparent contradiction. I will attempt to briefly sort out this
resolution in various domains (cosmological, computational, etc.), and
carefully identify where causal reasoning does and doesn't belong in our
analysis. A general discussion will follow (article). 
20200428 
Paweł Błasiak (IFJ PAN) Entanglement by identity, or interaction without ever
touching What is interaction and when does
it occur? Intuition suggests that the necessary condition for the interaction
of independently created particles is their direct touch or contact through
physical force carriers. In quantum mechanics, the result of the interaction
is entanglement — the appearance of nonclassical correlations in the system.
It seems that quantum theory allows entanglement of independent particles
without any contact. The fundamental identity of particles of the same kind
is responsible for this phenomenon. (article, slides) 
20200421 
Manfried Faber (TU Wien) Violation of Mermin's
version of a Bell inequality in a classical statistical model We investigate a classical statistical model
and show that Mermin's version of a Bell inequality is violated. We get this
violation, if the measurement modifies the ensemble, a feature, which is also
characteristic for measurement processes for quantum systems. (slides) 
20200414 
Bell theorem
discussion, short presentations: Richard Gill  continuation (additional
slides). Jarek Duda: 4 slides: 1)
derivation of Born rule for probability distribution inside Ising sequence,
2) Schrödinger equation from path ensembles, 3) how to use it to violate
Belllike inequalities, 4) how to save (local realistic) Lagrangian formalism
from conflict with Bell theorem (extended video) 
20200406 
Richard Gill (Leiden Univ.) Some thoughts on
Bell’s theorem and on Bell denialism I think that Bell’s theorem is a
true, simple (easy) mathematical theorem. NB Bell’s inequality(ies) is (are)
simple lemmas in the proof of the theorem. I have learnt a whole lot more
about the whole complex of mathematical, physical and philosophical issues,
by getting into fights with both respectable established scientists with
nonmainstream views, and with manifest amateur crackpots. This has given me
both mathematical and scientific insights, and insights into human
psychology; it feeds my amateur interests in psychology and metaphysics
(philosophy) and even religion. (slides) 
20200330 
Organizational
meeting, initial discussion: "Can
electrons objectively be in two places at once?" 