82 research outputs found
Zero-point fluctuations in rotation: Perpetuum mobile of the fourth kind without energy transfer
International audienceWe discuss a simple Casimir-type device for which the rotational energy reaches its global minimum when the device rotates about a certain axis rather than remains static. This unusual property is a direct consequence of the fact that the moment of inertia of zero-point vacuum fluctuations is a negative quantity (the rotational vacuum effect). Moreover, the device does not produce any work despite the fact that its equilibrium ground state corresponds to a permanent rotation. Counterintuitively, the device has no internally moving mechanical parts while its very existence is consistent with the laws of thermodynamics. We point out that such devices may possibly be constructed using carbon nanotubes. We call this "zero-point-driven" device as the perpetuum mobile of the fourth kind
Superconducting properties of vacuum in strong magnetic field
International audienceWe discuss superconducting phases of vacuum induced by strong magnetic field in the electroweak model and in Quantum Chromodynamics (QCD) at zero temperature. In these phases, the vacuum behaves as an anisotropic inhomogeneous superconductor which supports superconductivity along the axis of the magnetic field while in the transversal directions, the superconductivity does not exist. The magnetic-field-induced anisotropic superconductivity appears as a result of condensation of electrically charged spin-one particles, which are elementary W bosons in the case of the electroweak model and composite quark-antiquark pairs with quantum numbers of ρ -mesons in the case of QCD. Due to the anisotropic nature of superconductivity, the Meissner effect is absent. Intrinsic inhomogeneities of the superconducting ground state are characterized by ensembles of certain topological vortices in an analogy with a mixed Abrikosov state of a type-II superconductivit
Anomalous dispersion, superluminality, and instabilities in two-flavor theories with local non-Hermitian mass mixing
Pseudo-Hermitian field theories possess a global continuous “similarity” symmetry, interconnecting the theories with the same physical particle content and an identical mass spectrum. In their regimes with real spectra, within this family of similarity transformations, there is a map from the non-Hermitian theory to its Hermitian similarity partner. We promote the similarity transformation to a local symmetry, which requires the introduction of a new vector similarity field as a connection in the similarity space of non-Hermitian theories. In the case of non-Hermitian two-flavor scalar or fermion mixing and by virtue of a novel IR/UV mixing effect, the effect of inhomogeneous non-Hermiticity then reveals itself via anomalous dispersion, instabilities, and superluminal group velocities at very high momenta, thus setting an upper bound on the particle momentum propagating through inhomogeneous backgrounds characterized by Lagrangians with non-Hermitian mass matrices. Such a non-Hermitian extension of the Standard Model of particle physics, encoded in a weak inhomogeneity of the non-Hermitian part of the fermion mass matrix, may nevertheless provide us with a low-energy particle spectrum consistent with experimentally observed properties.<br/
IR/UV mixing from local similarity maps of scalar non-Hermitian field theories
We propose to "gauge" the group of similarity transformations that acts on a
space of non-Hermitian scalar theories. We introduce the "similarity gauge
field", which acts as a gauge connection on the space of non-Hermitian theories
characterized by (and equivalent to a Hermitian) real-valued mass spectrum.
This extension leads to new effects: if the mass matrix is not the same in
distant regions of space, but its eigenvalues coincide pairwise in both
regions, the particle masses stay constant in the whole spacetime, making the
model indistinguishable from a standard, low-energy and scalar Hermitian one.
However, contrary to the Hermitian case, the high-energy scalar particles
become unstable at a particular wavelength determined by the strength of the
emergent similarity gauge field. This instability corresponds to
momentum-dependent exceptional points, whose locations cannot be identified
from an analysis of the eigenvalues of the coordinate-dependent squared mass
matrix in isolation, as one might naively have expected. For a doublet of
scalar particles with masses of the order of 1 MeV and a similarity gauge
rotation of order unity at distances of 1 meter, the corrections to the masses
are about 10^{-7}eV, which makes no experimentally detectable imprint on the
low-energy spectrum. However, the instability occurs at 10^{18} eV,
suggestively in the energy range of detectable ultra-high-energy cosmic rays,
thereby making this truly non-Hermitian effect and its generalizations of
phenomenological interest for high-energy particle physics.Comment: 14 pages, 4 figures; v2 matches the published versio
Anomalous dispersion, superluminality and instabilities in two-flavour theories with local non-Hermitian mass mixing
Pseudo-Hermitian field theories possess a global continuous ``similarity''
symmetry, interconnecting the theories with the same physical particle content
and an identical mass spectrum. In their regimes with real spectra, within this
family of similarity transformations, there is a map from the non-Hermitian
theory to its Hermitian similarity partner. We promote the similarity
transformation to a local symmetry, which requires the introduction of a new
vector similarity field as a connection in the similarity space of
non-Hermitian theories. In the case of non-Hermitian two-flavour scalar or
fermion mixing, and by virtue of a novel IR/UV mixing effect, the effect of
inhomogeneous non-Hermiticity then reveals itself via anomalous dispersion,
instabilities and superluminal group velocities at very high momenta, thus
setting an upper bound on the particle momentum propagating through
inhomogeneous backgrounds characterised by Lagrangians with non-Hermitian mass
matrices. Such a non-Hermitian extension of the Standard Model of particle
physics, encoded in a weak inhomogeneity of the non-Hermitian part of the
fermion mass matrix, may nevertheless provide us with a low-energy particle
spectrum consistent with experimentally observed properties.Comment: 19 pages, 6 figure
Rigidly-rotating scalar fields: between real divergence and imaginary fractalization
The thermodynamics of rigidly rotating systems experience divergences when
the system dimensions transverse to the rotation axis exceed the critical size
imposed by the causality constraint. The rotation with imaginary angular
frequency, suitable for numerical lattice simulations in Euclidean
imaginary-time formalism, experiences fractalization of thermodynamics in the
thermodynamic limit, when the system's pressure becomes a fractal function of
the rotation frequency. Our work connects two phenomena by studying how
thermodynamics fractalizes as the system size grows. We examine an
analytically-accessible system of rotating massless scalar matter on a
one-dimensional ring and the numerically treatable case of rotation in the
cylindrical geometry and show how the ninionic deformation of statistics
emerges in these systems. We discuss a no-go theorem on analytical continuation
between real- and imaginary-rotating theories. Finally, we compute the moment
of inertia and shape deformation coefficients caused by the rotation of the
relativistic bosonic gas.Comment: 40 pages, 22 figures; accepted for publication in PRD; fractalization
video is available at https://youtu.be/Pk-S_10BM-
Anomalous dispersion, superluminality and instabilities in two-flavour theories with local non-Hermitian mass mixing
Pseudo-Hermitian field theories possess a global continuous ``similarity'' symmetry, interconnecting the theories with the same physical particle content and an identical mass spectrum. In their regimes with real spectra, within this family of similarity transformations, there is a map from the non-Hermitian theory to its Hermitian similarity partner. We promote the similarity transformation to a local symmetry, which requires the introduction of a new vector similarity field as a connection in the similarity space of non-Hermitian theories. In the case of non-Hermitian two-flavour scalar or fermion mixing, and by virtue of a novel IR/UV mixing effect, the effect of inhomogeneous non-Hermiticity then reveals itself via anomalous dispersion, instabilities and superluminal group velocities at very high momenta, thus setting an upper bound on the particle momentum propagating through inhomogeneous backgrounds characterised by Lagrangians with non-Hermitian mass matrices. Such a non-Hermitian extension of the Standard Model of particle physics, encoded in a weak inhomogeneity of the non-Hermitian part of the fermion mass matrix, may nevertheless provide us with a low-energy particle spectrum consistent with experimentally observed properties
A condensed matter realization of the axial magnetic effect
The axial magnetic effect, i.e., the generation of an energy current parallel
to an axial magnetic field coupling with opposite signs to left- and
right-handed fermions is a non-dissipative transport phenomenon intimately
related to the gravitational contribution to the axial anomaly. An axial
magnetic field emerges naturally in condensed matter in the so called Weyl
semi-metals. We present a measurable implementation of the axial magnetic
effect. We show that the edge states of a Weyl semimetal at finite temperature
possess a temperature dependent angular momentum in the direction of the vector
potential intrinsic to the system. Such a realization provides a plausible
context for the experimental confirmation of the elusive gravitational anomaly.Comment: 5 pages, 3 figure
Topological Solitons and Folded Proteins
We propose that protein loops can be interpreted as topological domain-wall
solitons. They interpolate between ground states that are the secondary
structures like alpha-helices and beta-strands. Entire proteins can then be
folded simply by assembling the solitons together, one after another. We
present a simple theoretical model that realizes our proposal and apply it to a
number of biologically active proteins including 1VII, 2RB8, 3EBX (Protein Data
Bank codes). In all the examples that we have considered we are able to
construct solitons that reproduce secondary structural motifs such as
alpha-helix-loop-alpha-helix and beta-sheet-loop-beta-sheet with an overall
root-mean-square-distance accuracy of around 0.7 Angstrom or less for the
central alpha-carbons, i.e. within the limits of current experimental accuracy.Comment: 4 pages, 4 figure
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