3,012 research outputs found
Euclidean Dynamical Symmetry in Nuclear Shape Phase Transitions
The Euclidean dynamical symmetry hidden in the critical region of nuclear
shape phase transitions is revealed by a novel algebraic F(5) description. With
a nonlinear projection, it is shown that the dynamics in the critical region of
the spherical--axial deformed and the spherical-- soft shape phase
transitions can indeed be manifested by this description, which thus provides a
unified symmetry--based interpretation of the critical phenomena in the region.Comment: 5 pages, 2 figures, 2 table
Isobaric Reconstruction of the Baryonic Acoustic Oscillation
In this paper, we report a significant recovery of the linear baryonic
acoustic oscillation (BAO) signature by applying the isobaric reconstruction
algorithm to the non-linear matter density field. Assuming only the
longitudinal component of the displacement being cosmologically relevant, this
algorithm iteratively solves the coordinate transform between the Lagrangian
and Eulerian frames without requiring any specific knowledge of the dynamics.
For dark matter field, it produces the non-linear displacement potential with
very high fidelity. The reconstruction error at the pixel level is within a few
percent, and is caused only by the emergence of the transverse component after
the shell-crossing. As it circumvents the strongest non-linearity of the
density evolution, the reconstructed field is well-described by linear theory
and immune from the bulk-flow smearing of the BAO signature. Therefore this
algorithm could significantly improve the measurement accuracy of the sound
horizon scale. For a perfect large-scale structure survey at redshift zero
without Poisson or instrumental noise, the fractional error is reduced by a
factor of 2.7, very close to the ideal limit with linear power spectrum and
Gaussian covariance matrix.Comment: 5 pages, 3 figures, accepted versio
Critical point symmetries in deformed odd-A nuclei
A scheme that elucidates the nature of critical point symmetries in deformed odd-A nuclei by linking them to critical point symmetries of neighboring even-even nuclei is introduced. Specifically, a new symmetry, called SX(3), is advanced that shows primary characteristics of an assumed strong-coupling limit for odd-A systems. It is found that the SX(3) symmetry can be used to identify the soft collective structures in odd-A system. A preliminary application of the new scheme to describe the lowest positive parity bands of 193Ir is also shown. © 2011 American Physical Society
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