S=1 antiferromagnetic Heisenberg chain with an axial-symmetry-breaking anisotropy

1991 ◽  
Vol 44 (18) ◽  
pp. 10385-10388 ◽  
Author(s):  
Tiôru Sakai ◽  
Minoru Takahashi
Keyword(s):  
Symmetry Breaking ◽  
Axial Symmetry ◽  
Heisenberg Chain

scholarly journals Molecular mechanism of symmetry breaking in a 3D model of a human epiblast

2018 ◽  
Author(s):  
Mijo Simunovic ◽  
Jakob J. Metzger ◽  
Fred Etoc ◽  
Anna Yoney ◽  
Albert Ruzo ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Axial Symmetry ◽  
3D Model ◽  
Epithelial To Mesenchymal Transition ◽  
Embryonic Stem ◽  
Primitive Streak ◽  
Molecular Evidence ◽  
Axis Formation ◽  
Mesenchymal Transition

ABSTRACTBreaking the anterior-posterior (AP) symmetry in mammals takes place at gastrulation. Much of the signaling network underlying this process has been elucidated in the mouse, however there is no direct molecular evidence of events driving axis formation in humans. Here, we use human embryonic stem cells to generate an in vitro 3D model of a human epiblast whose size, cell polarity, and gene expression are similar to a 10-day human epiblast. A defined dose of bone mor-phogenetic protein 4 (BMP4) spontaneously breaks axial symmetry, and induces markers of the primitive streak and epithelial to mesenchymal transition. By gene knockouts and live-cell imaging we show that, downstream of BMP4, WNT3 and its inhibitor DKK1 play key roles in this process. Our work demonstrates that a model human epiblast can break axial symmetry despite no asymmetry in the initial signal and in the absence of extraembryonic tissues or maternal cues. Our 3D model opens routes to capturing molecular events underlying axial symmetry breaking phenomena, which have largely been unexplored in model human systems.

scholarly journals Probing Axial Symmetry Breaking in the Galaxy with Gaia Data Release 2

2020 ◽  
Vol 893 (2) ◽  
pp. 105
Author(s):  
Austin Hinkel ◽  
Susan Gardner ◽  
Brian Yanny
Keyword(s):  
Symmetry Breaking ◽  
Axial Symmetry ◽  
Data Release ◽  
The Galaxy

scholarly journals Axial symmetry breaking of Saturn’s thermosphere

2012 ◽  
Vol 422 (2) ◽  
pp. 1460-1488 ◽  
Author(s):  
C. G. A. Smith ◽  
N. Achilleos
Keyword(s):  
Symmetry Breaking ◽  
Axial Symmetry

Axial-symmetry breaking in constrained membranes

2009 ◽  
Vol 367 (1902) ◽  
pp. 3363-3378 ◽  
Author(s):  
Paolo Biscari ◽  
Gaetano Napoli
Keyword(s):  
Symmetry Breaking ◽  
Axial Symmetry ◽  
Lipid Membrane ◽  
Equilibrium Configuration ◽  
Critical Threshold ◽  
Fourier Mode ◽  
Planar Approximation ◽  
Axisymmetric Mode ◽  
Equilibrium Shapes ◽  
Energy Minimizers

We study the equilibrium shapes of a lipid membrane, attached to a fixed circular substrate. We show how the weakening of the boundary conditions is able to break the axial symmetry of the optimal equilibrium configuration. We derive the critical threshold of the symmetry-breaking transition, and obtain the analytical expression of the free-energy minimizers in the quasi-planar approximation. Metastable states turn out to contain contributions only from the axisymmetric mode, and at most one single non-trivial Fourier mode.

scholarly journals U(1)symmetry breaking and violated axial symmetry inTlCuCl3and other insulating spin systems

2009 ◽  
Vol 79 (1) ◽  
Author(s):  
Raffaele Dell’Amore ◽  
Andreas Schilling ◽  
Karl Krämer
Keyword(s):  
Symmetry Breaking ◽  
Axial Symmetry ◽  
Spin Systems

scholarly journals Evidence of cosmic strings by the observation of the alignment of quasar polarization axes on Mpc scale

2018 ◽  
Vol 27 (09) ◽  
pp. 1850094 ◽  
Author(s):  
Reinoud Jan Slagter
Keyword(s):  
Symmetry Breaking ◽  
Gauge Field ◽  
Cosmic String ◽  
Axial Symmetry ◽  
Approximation Scheme ◽  
Azimuthal Angle ◽  
Goldstone Boson ◽  
Second Order ◽  
Compact Objects ◽  
Warp Factor

The recently found alignment of the polarization axes (PA) of quasars in large quasar groups (LQGs) on Mpc scales can be explained by general relativistic cosmic string networks. By considering the cosmic string as a result of spontaneous symmetry breaking of the gauged U(1) abelian Higgs model with topological charge [Formula: see text], many stability features of [Formula: see text]-vortex solutions of superconductivity can be taken over. Decay of the high multiplicity ([Formula: see text]) super-conducting vortex into a lattice of [Formula: see text] vortices of unit magnetic flux is energetically favorable. The temporarily broken axial symmetry will leave an imprint of a preferred azimuthal-angle on the lattice. The stability of the lattice depends critically on the parameters of the model, especially when gravity comes into play. In order to handle the strong nonlinear behavior of the time-dependent coupled field equations of gravity and the scalar-gauge field, we will use a high-frequency approximation scheme to second order on a warped 5D axially symmetric spacetime with the scalar-gauge field residing on the brane. We consider different winding numbers for the subsequent orders of perturbations of the scalar field. A profound contribution to the energy–momentum tensor comes from the bulk spacetime and can be understood as “dark”-energy. The cosmic string becomes super-massive by the contribution of the 5D Weyl tensor on the brane and the stored azimuthal preferences will not fade away. During the recovery to axial symmetry, gravitational and electro-magnetic radiation will be released. The perturbative appearance of a nonzero energy–momentum component [Formula: see text] can be compared with the phenomenon of bifurcation along the Maclaurin–Jacobi sequence of equilibrium ellipsoids of self-gravitating compact objects, signaling the onset of secular instabilities. There is a kind of similarity with the Goldstone-boson modes of spontaneously broken symmetries of continuous groups. The recovery of the SO(2) symmetry from the equatorial eccentricity takes place on a time-scale comparable with the emission of gravitational waves. The emergent azimuthal-angle dependency in our model can be used to explain the aligned PA in LQGs on Mpc scales. Spin axis direction perpendicular to the major axes of LQGs when the richness decreases can be explained as a second-order effect in our approximation scheme by the higher multiplicity terms. The preferred directions are modulo [Formula: see text], with [Formula: see text] being an integer dependent on the [Formula: see text]th order of approximation. When more data of quasars of high redshift becomes available, one could prove that the alignment emerged after the symmetry breaking scale and must have a cosmological origin. The effect of the warp factor on the second-order perturbations could also be an indication of the existence of extra large dimensions.

Unveiling stability of multiple filamentation caused by axial symmetry breaking of polarization

2016 ◽  
Vol 4 (5) ◽  
pp. B29 ◽  
Author(s):  
Si-Min Li ◽  
Zhi-Cheng Ren ◽  
Ling-Jun Kong ◽  
Sheng-Xia Qian ◽  
Chenghou Tu ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Axial Symmetry ◽  
Multiple Filamentation
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