421 research outputs found
Stokes matrices for the quantum differential equations of some Fano varieties
The classical Stokes matrices for the quantum differential equation of
projective n-space are computed, using multisummation and the so-called
monodromy identity. Thus, we recover the results of D. Guzzetti that confirm
Dubrovin's conjecture for projective spaces. The same method yields explicit
formulas for the Stokes matrices of the quantum differential equations of
smooth Fano hypersurfaces in projective n-space and for weighted projective
spaces.Comment: 20 pages. Introduction has been changed. Small corrections in the
tex
Seidel elements and mirror transformations
The goal of this article is to give a precise relation between the mirror
symmetry transformation of Givental and the Seidel elements for a smooth
projective toric variety with nef. We show that the Seidel elements
entirely determine the mirror transformation and mirror coordinates.Comment: 36 pages. We corrected several issues as pointed out by the refere
Accurate determination of blackbody radiation shifts in a strontium molecular lattice clock
Molecular lattice clocks enable the search for new physics, such as fifth forces or temporal variations of fundamental constants, in a manner complementary to atomic clocks. Blackbody radiation (BBR) is a major contributor to the systematic error budget of conventional atomic clocks and is notoriously difficult to characterize and control. Here, we combine infrared Stark-shift spectroscopy in a molecular lattice clock and modern quantum chemistry methods to characterize the polarizabilities of the Sr2 molecule from dc to infrared. Using this description, we determine the static and dynamic blackbody radiation shifts for all possible vibrational clock transitions to the 10−16 level. This constitutes an important step toward millihertz-level molecular spectroscopy in Sr2 and provides a framework for evaluating BBR shifts in other homonuclear molecules
Precise Determination of Blackbody Radiation Shifts in a Strontium Molecular Lattice Clock
Molecular lattice clocks enable the search for new physics, such as fifth
forces or temporal variations of fundamental constants, in a manner
complementary to atomic clocks. Blackbody radiation (BBR) is a major
contributor to the systematic error budget of conventional atomic clocks and is
notoriously difficult to characterize and control. Here, we combine infrared
Stark-shift spectroscopy in a molecular lattice clock and modern quantum
chemistry methods to characterize the polarizabilities of the Sr molecule
from dc to infrared. Using this description, we determine the static and
dynamic blackbody radiation shifts for all possible vibrational clock
transitions to the level. This constitutes an important step towards
mHz-level molecular spectroscopy in Sr, and provides a framework for
evaluating BBR shifts in other homonuclear molecules.Comment: 6 pages, 4 figures, updated reference
LEUKEMIA-ASSOCIATED TRANSPLANTATION ANTIGENS RELATED TO MURINE LEUKEMIA VIRUS : THE X.1 SYSTEM: IMMUNE RESPONSE CONTROLLED BY A LOCUS LINKED TOH-2
Two BALB radiation leukemias are strongly rejected by hybrids of BALB with certain other mouse strains, although BALB mice themselves exhibit no detectable resistance whatever. Hybrids immunized with progressively increased inocula are resistant to 200 x 106 or more leukemia cells; their serum is cytotoxic for the leukemia cells in vitro and protects BALB mice against challenge with these BALB leukemias. The antigenic system thus identified has been named X.1. In (BALB x B6) hybrids the major determinant of resistance was shown to be a B6 gene in the K region of H-2. This is likely to be the Rgv-1 (Resistance to gross virus) locus of Lilly, which may thus be identified in this case as an Ir (Immune response) allele conferring ability to respond to X.1 antigen on MuLV and leukemia cells, and so responsible for production of X.1 antibody and the rejection of X.1+ leukemia cells by hybrid mice. Immunoelectron microscopy with X.1 antiserum (from immunized hybrids) shows labeling both on the cell surface and on virions produced by the leukemia cells. It is not known whether X.1 comprises only one or more than one antigen. Three radiation-induced BALB leukemias, one A strain radiation-induced leukemia, and 15/15 AKR primary spontaneous leukemias were typed X.1+ by the cytotoxicity test. Several other leukemias, including one induced by passage A Gross virus and one long-transplanted AKR ascites leukemia carried in (B6 x AKR)F1 hybrids, were X.1-. Normal mice of strains with a high incidence of leukemia and one other strain (129) express X.1 antigen, but evidently in amounts too small for certain detection in vitro; by the method of absorption in vivo, however, these strains could be typed X.1+ and other strains X.1-. We ascribe the X.1 antigen system tentatively to a sub-type of MuLV that is not passage A Gross virus and is probably not the dominant sub-type in strains with a high incidence of leukemia. After repeated passage in hybrids, one of the BALB leukemias became relatively resistant to rejection by the hybrid, partially lost its sensitivity to X.1 antiserum in vitro, and in electron micrographs was seen to produce fewer virions. The serum of untreated (BALB x B6) hybrids often contains cytotoxic antibody against leukemia cells, some of it probably anti-X.1. But another commonly occurring antibody, which is cytotoxic for C57BL leukemia EL4, appears to belong to another (undefined) system
Virtual Structure Constants as Intersection Numbers of Moduli Space of Polynomial Maps with Two Marked Points
In this paper, we derive the virtual structure constants used in mirror
computation of degree k hypersurface in CP^{N-1}, by using localization
computation applied to moduli space of polynomial maps from CP^{1} to CP^{N-1}
with two marked points. We also apply this technique to non-nef local geometry
O(1)+O(-3)->CP^{1} and realize mirror computation without using Birkhoff
factorization.Comment: 10 pages, latex, a minor change in Section 4, English is refined,
Some typing errors in Section 3 are correcte
A terahertz vibrational molecular clock with systematic uncertainty at the level
Neutral quantum absorbers in optical lattices have emerged as a leading
platform for achieving clocks with exquisite spectroscopic resolution. However,
the studies of these clocks and their systematic shifts have so far been
limited to atoms. Here, we extend this architecture to an ensemble of diatomic
molecules and experimentally realize an accurate lattice clock based on pure
molecular vibration. We evaluate the leading systematics, including the
characterization of nonlinear trap-induced light shifts, achieving a total
systematic uncertainty of . The absolute frequency of the
vibrational splitting is measured to be 31 825 183 207 592.8(5.1) Hz, enabling
the dissociation energy of our molecule to be determined with record accuracy.
Our results represent an important milestone in molecular spectroscopy and
THz-frequency standards, and may be generalized to other neutral molecular
species with applications for fundamental physics, including tests of molecular
quantum electrodynamics and the search for new interactions.Comment: 17 pages, 8 figure
Lattice QCD analysis for Faddeev-Popov eigenmodes in terms of gluonic momentum components in the Coulomb gauge
We analyze the relation between Faddeev-Popov eigenmodes and gluon-momentum
components in the Coulomb gauge using SU(3) lattice QCD. In the Coulomb gauge,
the color-Coulomb energy is largely enhanced by near-zero Faddeev-Popov
eigenmodes, which would lead to the confining potential. By the
ultraviolet-momentum gluon cut, the color-Coulomb energy and the Faddeev-Popov
spectrum are almost unchanged. In contrast to the ultraviolet insensitivity,
the color-Coulomb energy and the Faddeev-Popov eigenmodes drastically change by
infrared-momentum gluon cut. Without infrared gluons, the color-Coulomb energy
tends to become non-confining, and near-zero Faddeev-Popov eigenmodes vanish.
We also investigate the full FP eigenmodes, and find that infrared gluons
widely influence both high and low Faddeev-Popov eigenmodes.Comment: 8 pages, 5 figure
Mirror Map as Generating Function of Intersection Numbers: Toric Manifolds with Two K\"ahler Forms
In this paper, we extend our geometrical derivation of expansion coefficients
of mirror maps by localization computation to the case of toric manifolds with
two K\"ahler forms. Especially, we take Hirzebruch surfaces F_{0}, F_{3} and
Calabi-Yau hypersurface in weighted projective space P(1,1,2,2,2) as examples.
We expect that our results can be easily generalized to arbitrary toric
manifold.Comment: 45 pages, 2 figures, minor errors are corrected, English is refined.
Section 1 and Section 2 are enlarged. Especially in Section 2, confusion
between the notion of resolution and the notion of compactification is
resolved. Computation under non-zero equivariant parameters are added in
Section
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