4,235 research outputs found
Comments on "The Role of the Central Asian Mountains on the Midwinter Suppression of North Pacific Storminess" - Reply
We thank Chang and Lin for their thoughtful and
constructive comments on our study (Park et al. 2010).
In Park et al. (2010), we did not explicitly state that the
topography-forced stationary waves are the direct cause
for the reduced downstream transient eddy kinetic energy
(EKE). The response of stationary waves to topography
may saturate even with a relatively small mountain (Cook
and Held 1992); furthermore, their magnitudes are much
smaller than thermally forced stationary waves (Chang
2009; Held et al. 2002). Instead, we suggest that quasistationary waves generated by the central Asian mountains may strongly affect North Pacific storminess by
changing the year-to-year variability of westerly winds
over the eastern Eurasian continent. Observational analyses
indicate that the midwinter suppression of North
Pacific storminess does not occur every year. Some years
experience stronger and more meridionally confined
zonal winds over the western North Pacific, leading to
stronger midwinter suppression (Harnik and Chang
2004; Nakamura and Sampe 2002)
Cauchy problem for the Boltzmann-BGK model near a global Maxwellian
In this paper, we are interested in the Cauchy problem for the Boltzmann-BGK
model for a general class of collision frequencies. We prove that the
Boltzmann-BGK model linearized around a global Maxwellian admits a unique
global smooth solution if the initial perturbation is sufficiently small in a
high order energy norm. We also establish an asymptotic decay estimate and
uniform -stability for nonlinear perturbations.Comment: 26 page
Novel duality in disorder driven local quantum criticality
We find that competition between random Kondo and random magnetic
correlations results in a quantum phase transition from a local Fermi liquid to
a spin liquid. The local charge susceptibility turns out to have exactly the
same critical exponent as the local spin susceptibility, suggesting novel
duality between the Kondo singlet phase and the critical local moment state
beyond the Landau-Ginzburg-Wilson symmetry breaking framework. This leads us to
propose an enhanced symmetry at the local quantum critical point, described by
an O(4) vector for spin and charge. The symmetry enhancement serves mechanism
of electron fractionalization in critical impurity dynamics, where such
fractionalized excitations are identified with topological excitations
The Mechanical Impact of the Tibetan Plateau on the Seasonal Evolution of the South Asian Monsoon
The impact of the Tibetan Plateau on the South Asian monsoon is examined using a hierarchy of atmospheric general circulation models. During the premonsoon season and monsoon onset (April–June), when westerly winds over the Southern Tibetan Plateau are still strong, the Tibetan Plateau triggers early monsoon rainfall downstream, particularly over the Bay of Bengal and South China. The downstream moist convection is accompanied by strong monsoonal low-level winds. In experiments where the Tibetan Plateau is removed, monsoon onset occurs about a month later, but the monsoon circulation becomes progressively stronger and reaches comparable strength during the mature phase. During the mature and decaying phase of monsoon (July–September), when westerly winds over the Southern Tibetan Plateau almost disappear, monsoon circulation strength is not much affected by the presence of the Tibetan Plateau.
A dry dynamical core with east–west-oriented narrow mountains in the subtropics consistently simulates downstream convergence with background zonal westerlies over the mountain. In a moist atmosphere, the mechanically driven downstream convergence is expected to be associated with significant moisture convergence. The authors speculate that the mechanically driven downstream convergence in the presence of the Tibetan Plateau is responsible for zonally asymmetric monsoon onset, particularly over the Bay of Bengal and South China
The D0 same-charge dimuon asymmetry and possibile new CP violation sources in the system
Recently, the D0 collaboration reported a large CP violation in the same-sign
dimuon charge asymmetry which has the deviation from the value
estimated in the Standard Model. In this paper, several new physics models are
considered: the MSSM, two Higgs doublet model, the recent dodeca model, and a
new model. Generally, it is hard to achieve such a large CP violation
consistently with other experimental constraints. We find that a scheme with
extra non-anomalous U(1) gauge symmetry is barely consistent. In general,
the extra gauge boson induces the flavor changing neutral current
interactions at tree level, which is the basic reason allowing a large new
physics CP violation. To preserve the U(1) symmetry at high energy,
SU(2) singlet exotic heavy quarks of mass above 1 TeV and the Standard
Model gauge singlet scalars are introduced.Comment: 12 pages, 13 figure
Measurement of statistical evidence on an absolute scale following thermodynamic principles
Statistical analysis is used throughout biomedical research and elsewhere to
assess strength of evidence. We have previously argued that typical outcome
statistics (including p-values and maximum likelihood ratios) have poor
measure-theoretic properties: they can erroneously indicate decreasing evidence
as data supporting an hypothesis accumulate; and they are not amenable to
calibration, necessary for meaningful comparison of evidence across different
study designs, data types, and levels of analysis. We have also previously
proposed that thermodynamic theory, which allowed for the first time derivation
of an absolute measurement scale for temperature (T), could be used to derive
an absolute scale for evidence (E). Here we present a novel
thermodynamically-based framework in which measurement of E on an absolute
scale, for which "one degree" always means the same thing, becomes possible for
the first time. The new framework invites us to think about statistical
analyses in terms of the flow of (evidential) information, placing this work in
the context of a growing literature on connections among physics, information
theory, and statistics.Comment: Final version of manuscript as published in Theory in Biosciences
(2013
Superconductivity from a non-Fermi liquid metal : Kondo fluctuation mechanism in the slave-fermion theory
We find new mechanism of superconductivity beyond the spin-fluctuation
theory, the standard model for unconventional superconductivity in the weak
coupling approach, where Kondo fluctuations result in multi-gap
superconductivity around an antiferromagnetic quantum critical point of the
slave-fermion theory. Fingerprints of the hybridization mechanism are two kinds
of resonance modes in not only spin but also charge fluctuations, originating
from pairing of conduction electrons and spinless holons,
respectively, thus differentiated from the spin-fluctuation mechanism. We show
that the ratio between each superconducting gap for conduction electrons
and holons and the transition temperature is
and , remarkably consistent with
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