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Non-Hermitian Hamiltonians with unitary and antiunitary symmetries
(Academic Press Inc Elsevier Science, 2014-03)
We analyse several non-Hermitian Hamiltonians with antiunitary symmetry from the point of view of their point-group symmetry. It enables us to predict the degeneracy of the energy levels and to reduce the dimension of the ...
A física de partículas elementares e o Prêmio Nobel de física 2008
(2008-10-01)
The 2008 Nobel prize of physics pay tribute to three theoretical physicist by their work related to some symmetries of Nature. We briefly comments the importance of these works and the context in which they were done. ...
Parity-time symmetry broken by point-group symmetry
(American Institute of Physics, 2014-06)
We discuss a parity-time (PT) symmetric Hamiltonian with complex eigenvalues. It is based on the dimensionless Schrödinger equation for a particle in a square box with the PT-symmetric potential V(x, y) = iaxy. Perturbation ...
A THEORY OF GRAVITY WITH BROKEN SYMMETRY
(Natl Research Council Canada, 1990-10-01)
The Dirac Equation in Six-dimensional SO(3,3) Symmetry Group and a Non-chiral "Electroweak" Theory
(Springer/plenum PublishersNew YorkEUA, 2010)
Three PT-symmetric Hamiltonians with completely different spectra
(Academic Press Inc Elsevier Science, 2015-12)
We discuss three Hamiltonians, each with a central-field part H0 and a PT-symmetric perturbation igz. When H0 is the isotropic Harmonic oscillator the spectrum is real for all g because H is isospectral to H0+g2/2. When ...
Electromagnetic response of layered superconductors with broken lattice inversion symmetry
(American Physical SocCollege PkEUA, 2004)
Broken discrete symmetries in a frustrated honeycomb antiferromagnet
(American Physical Society, 2013-03)
We study the magnetic phase diagram of the J1-J2 Heisenberg antiferromagnet on a honeycomb lattice at the strongly frustrated point J2/J1=1/2 using large-scale Monte Carlo simulations. At low temperatures we find three ...
Quaternionic representation of the genetic code
(Elsevier, 2016-03)
A heuristic diagram of the evolution of the standard genetic code is presented. It incorporates, in a way that resembles the energy levels of an atom, the physical notion of broken symmetry and it is consistent with original ...
On the exactness of soft theorems
(2017-12-01)
Soft behaviours of S-matrix for massless theories reflect the underlying symmetry principle that enforces its masslessness. As an expansion in soft momenta, sub-leading soft theorems can arise either due to (I) unique ...