738 research outputs found
Canonical Equivariant Cohomology Classes Generating Zeta Values of Totally Real Fields
It is known that the special values at nonpositive integers of a Dirichlet
-function may be expressed using the generalized Bernoulli numbers, which
are defined by a canonical generating function. The purpose of this article is
to consider the generalization of this classical result to the case of Hecke
-functions of totally real fields. Hecke -functions may be expressed
canonically as a finite sum of zeta functions of Lerch type. By combining the
non-canonical multivariable generating functions constructed by Shintani, we
newly construct a canonical class, which we call the Shintani generating class,
in the equivariant cohomology of an algebraic torus associated to the totally
real field. Our main result states that the specializations at torsion points
of the derivatives of the Shintani generating class give values at nonpositive
integers of the zeta functions of Lerch type. This result gives the insight
that the correct framework in the higher dimensional case is to consider higher
equivariant cohomology classes instead of functions.Comment: 18 pages, Updated version with minor correction
-adic Polylogarithms and -adic Hecke -functions for Totally Real Fields
The purpose of this article is to newly define the -adic polylogarithm as
an equivariant class in the cohomology of a certain infinite disjoint union of
algebraic tori associated to a totally real field. We will then express the
special values of -adic -functions interpolating nonpositive values of
Hecke -functions of the totally real field in terms of special values of
these -adic polylogarithms.Comment: 32 page
〈Original Papers〉Modulation of diurnal precipitation occurrences observed in the Tibetan Plateau during monsoon season of 1998
Relations between the diurnal change of the radar echo areas and surface condition were examined at the central Tibetan Plateau during the monsoon season in 1998. During the late June, under the synoptic conditions of prevailing surface heat low with Tibetan anticyclone, a weekly time scale modulation was clearly observed in the diurnal changes of the convective activity, such as the delay of the daytime precipitation clouds toward evening, especially over the southern mountainous areas. The feature was confirmed by the diurnal weather changes indicated by multiple surface meteorological elements. Surface energy flux and hydro-meteorological measurements showed that the modulation was associated with weekly scale reducing of morning sensible heating and suppression of the planetary boundary layer development during midday. The increase of soil-surface moisture in the morning was also confirmed by the surface albedo measurements. Therefore, we hypothesize the cause of the delay of daytime precipitation by land-surface moistening due to precipitation in the previous days
All-or-none switching of transcriptional activity on single DNA molecules caused by a discrete conformational transition
Recently, it has been confirmed that long duplex DNA molecules with sizes
larger than several tens of kilo-base pairs (kbp), exhibit a discrete
conformational transition from an elongated coil state to a compact globule
state upon the addition of various kinds of chemical species that usually
induce DNA condensation. In this study, we performed a single-molecule
observation on a large DNA, Lambda ZAP II DNA (ca. 41 kbp), in a solution
containing RNA polymerase and substrates along with spermine, a tetravalent
cation, at different concentrations, by use of fluorescence staining of both
DNA and RNA. We found that transcription, or RNA production, is completely
inhibited in the compact state, but is actively performed in the unfolded coil
state. Such an all-or-none effect on transcriptional activity induced by the
discrete conformational transition of single DNA molecules is discussed in
relation to the mechanism of the regulation of large-scale genetic activity.Comment: 14 pages, 2 figure
Response to "Comment on `Quantum-confinement effects on the optical and dielectric properties for mesocrystals of BaTiO3 and SrBi2Ta2O9\u27"
In this reply, the authors show that the argument by Scott regarding the band gap of bulk SrBi2Ta2O9 (SBT) is not based on concrete evidence. The authors will also show additional data from a Raman study of a powdered SBT sample to prove that the surface of the specimen was not covered by Bi2O3
Polaron Masses in CH₃NH₃PbX₃ Perovskites Determined by Landau Level Spectroscopy in Low Magnetic Fields
次世代太陽電池材料 ペロブスカイト半導体中の「電子の重さ」の評価に成功 --太陽電池やLED応用へ向けてさらなる期待--. 京都大学プレスリリース. 2021-06-14.We investigate the electron-phonon coupling in CH₃NH₃PbX₃ lead halide perovskites through the observation of Landau levels and high-order excitons at weak magnetic fields, where the cyclotron energy is significantly smaller than the longitudinal optical phonon energy. The reduced masses of the carriers and the exciton binding energies obtained from these data are clearly influenced by polaron formation. We analyze the field-dependent polaronic and excitonic properties, and show that they can be quantitatively reproduced by the Fröhlich large polaron model
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