973 research outputs found
CR-Invariants and the Scattering Operator for Complex Manifolds with Boundary
The purpose of this paper is to describe certain CR-covariant differential
operators on a strictly pseudoconvex CR manifold as residues of the
scattering operator for the Laplacian on an ambient complex K\"{a}hler manifold
having as a `CR-infinity.' We also characterize the CR -curvature in
terms of the scattering operator. Our results parallel earlier results of
Graham and Zworski \cite{GZ:2003}, who showed that if is an asymptotically
hyperbolic manifold carrying a Poincar\'{e}-Einstein metric, the -curvature
and certain conformally covariant differential operators on the `conformal
infinity' of can be recovered from the scattering operator on . The
results in this paper were announced in \cite{HPT:2006}.Comment: 32 page
Dependence of the density of states outer measure on the potential for deterministic Schr\"odinger operators on graphs with applications to ergodic and random models
We continue our study of the dependence of the density of states measure and
related spectral functions of Schr\"odinger operators on the potential. Whereas
our earlier work focused on random Schr\"odinger operators, we extend these
results to Schr\"odinger operators on infinite graphs with deterministic
potentials and ergodic potentials, and improve our results for random
potentials. In particular, we prove the Lipschitz continuity of the DOSm for
random Schr\"odinger operators on the lattice, recovering results of
\cite{kachkovskiy, shamis}. For our treatment of deterministic potentials, we
first study the density of states outer measure (DOSoM), defined for all
Schr\"odinger operators, and prove a deterministic result of the modulus of
continuity of the DOSoM with respect to the potential. We apply these results
to Schr\"odinger operators on the lattice and the Bethe lattice. In the
former case, we prove the Lipschitz continuity of the DOSoM, and in the latter
case, we prove that the DOSoM is -log-H\"older continuous. Our
technique combines the abstract Lipschitz property of one-parameter families of
self-adjoint operators with a new finite-range reduction that allows us to
study the dependency of the DOSoM and related functions on only finitely-many
variables and captures the geometry of the graph at infinity.Comment: Related to arXiv:1804.02444 and arXiv:1904.01118 by the authors; New
appendices C and D are added and typos corrected. Appendix C discusses
inequalities between the metric of weak convergence of measures and the
Kantorovich-Rubinstein-Wasserstein metric. Appendix D presents results on
continuity of the Hausdorff distance between two spectra with respect to the
potential
CD8+ immunodominance among Epstein-Barr virus lytic cycle antigens directly reflects the efficiency of antigen presentation in lytically infected cells
Antigen immunodominance is an unexplained feature of CD8+ T cell responses to herpesviruses, which are agents whose lytic replication involves the sequential expression of immediate early (IE), early (E), and late (L) proteins. Here, we analyze the primary CD8 response to Epstein-Barr virus (EBV) infection for reactivity to 2 IE proteins, 11 representative E proteins, and 10 representative L proteins, across a range of HLA backgrounds. Responses were consistently skewed toward epitopes in IE and a subset of E proteins, with only occasional responses to novel epitopes in L proteins. CD8+ T cell clones to representative IE, E, and L epitopes were assayed against EBV-transformed lymphoblastoid cell lines (LCLs) containing lytically infected cells. This showed direct recognition of lytically infected cells by all three sets of effectors but at markedly different levels, in the order IE > E ≫ L, indicating that the efficiency of epitope presentation falls dramatically with progress of the lytic cycle. Thus, EBV lytic cycle antigens display a hierarchy of immunodominance that directly reflects the efficiency of their presentation in lytically infected cells; the CD8+ T cell response thereby focuses on targets whose recognition leads to maximal biologic effect
Use of methods for specifying the target difference in randomised controlled trial sample size calculations : Two surveys of trialists' practice
© The Author(s), 2014.Peer reviewedPublisher PD
Shapes of leading tunnelling trajectories for single-electron molecular ionization
Based on the geometrical approach to tunnelling by P.D. Hislop and I.M. Sigal
[Memoir. AMS 78, No. 399 (1989)], we introduce the concept of a leading
tunnelling trajectory. It is then proven that leading tunnelling trajectories
for single-active-electron models of molecular tunnelling ionization (i.e.,
theories where a molecular potential is modelled by a single-electron
multi-centre potential) are linear in the case of short range interactions and
"almost" linear in the case of long range interactions. The results are
presented on both the formal and physically intuitive levels. Physical
implications of the obtained results are discussed.Comment: 14 pages, 5 figure
Anomalous Scale Dimensions from Timelike Braiding
Using the previously gained insight about the particle/field relation in
conformal quantum field theories which required interactions to be related to
the existence of particle-like states associated with fields of anomalous
scaling dimensions, we set out to construct a classification theory for the
spectra of anomalous dimensions. Starting from the old observations on
conformal superselection sectors related to the anomalous dimensions via the
phases which appear in the spectral decomposition of the center of the
conformal covering group we explore the possibility
of a timelike braiding structure consistent with the timelike ordering which
refines and explains the central decomposition. We regard this as a preparatory
step in a new construction attempt of interacting conformal quantum field
theories in D=4 spacetime dimensions. Other ideas of constructions based on the
- or the perturbative SYM approach in their relation to the
present idea are briefly mentioned.Comment: completely revised, updated and shortened replacement, 24 pages
tcilatex, 3 latexcad figure
Singular Modes of the Electromagnetic Field
We show that the mode corresponding to the point of essential spectrum of the
electromagnetic scattering operator is a vector-valued distribution
representing the square root of the three-dimensional Dirac's delta function.
An explicit expression for this singular mode in terms of the Weyl sequence is
provided and analyzed. An essential resonance thus leads to a perfect
localization (confinement) of the electromagnetic field, which in practice,
however, may result in complete absorption.Comment: 14 pages, no figure
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