273 research outputs found
Fisher's scaling relation above the upper critical dimension
Fisher's fluctuation-response relation is one of four famous scaling formulae
and is consistent with a vanishing correlation-function anomalous dimension
above the upper critical dimension d_c. However, it has long been known that
numerical simulations deliver a negative value for the anomalous dimension
there. Here, the apparent discrepancy is attributed to a distinction between
the system-length and correlation- or characteristic-length scales. On the
latter scale, the anomalous dimension indeed vanishes above d_c and Fisher's
relation holds in its standard form. However, on the scale of the system
length, the anomalous dimension is negative and Fisher's relation requires
modification. Similar investigations at the upper critical dimension, where
dangerous irrelevant variables become marginal, lead to an analogous pair of
Fisher relations for logarithmic-correction exponents. Implications of a
similar distinction between length scales in percolation theory above d_c and
for the Ginzburg criterion are briefly discussed.Comment: Published version has 6 pages, 2 figure
Looking for the Logarithms in Four-Dimensional Nambu-Jona-Lasinio Models
We study the problem of triviality in the four dimensional Nambu-Jona-Lasinio
model with discrete chiral symmetry using both large-N expansions and lattice
simulations. We find that logarithmic corrections to scaling appear in the
equation of state as predicted by the large-N expansion. The data from
lattice simulations is sufficiently accurate to distinguish logarithmically
trivial scaling from power law scaling. Simulations on different lattice sizes
reveal an interesting interplay of finite size effects and triviality. We argue
that such effects are qualitatively different for theories based on fundamental
scalar rather than fermion fields. Several lessons learned here can be applied
to simulations and analyses of more challenging field theories.Comment: 25 pages, 14 ps figure
Role of Fourier Modes in Finite-Size Scaling above the Upper Critical Dimension
Renormalization-group theory stands, since over 40 years, as one of the
pillars of modern physics. As such, there should be no remaining doubt
regarding its validity. However, finite-size scaling, which derives from it,
has long been poorly understood above the upper critical dimension in
models with free boundary conditions. Besides its fundamental significance for
scaling theories, the issue is important at a practical level because
finite-size, statistical-physics systems, with free boundaries above , are
experimentally accessible with long-range interactions. Here we address the
roles played by Fourier modes for such systems and show that the current
phenomenological picture is not supported for all thermodynamic observables
either with free or periodic boundaries. Instead, the correct picture emerges
from a sector of the renormalization group hitherto considered unphysical.Comment: 10 pages, 2 figure
International Pediatric Otolaryngology Group (IPOG) consensus recommendations: Hearing loss in the pediatric patient
OBJECTIVE
To provide recommendations for the workup of hearing loss in the pediatric patient.
METHODS
Expert opinion by the members of the International Pediatric Otolaryngology Group.
RESULTS
Consensus recommendations include initial screening and diagnosis as well as the workup of sensorineural, conductive and mixed hearing loss in children. The consensus statement discusses the role of genetic testing and imaging and provides algorithms to guide the workup of children with hearing loss.
CONCLUSION
The workup of children with hearing loss can be guided by the recommendations provided herei
Benefits of a Multidisciplinary Survivor Clinic in Addressing Quality of Life After Cancer Treatment
The Ctf18 RFC-like complex positions yeast telomeres but does not specify their replication time
Peer reviewedPreprin
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