773 research outputs found
Note on clock synchronization and Edwards transformations
Edwards transformations relating inertial frames with arbitrary clock
synchronization are reminded and put in more general setting. Their group
theoretical context is described.Comment: 11 pages, no figures; final version, to appear in Foundations of
Physics Letter
Eliashberg's proof of Cerf's theorem
Following a line of reasoning suggested by Eliashberg, we prove Cerf's
theorem that any diffeomorphism of the 3-sphere extends over the 4-ball. To
this end we develop a moduli-theoretic version of Eliashberg's
filling-with-holomorphic-discs method.Comment: 32 page
Two-loop Renormalization for Nonanticommutative N=1/2 Supersymmetric WZ Model
We study systematically, through two loops, the divergence structure of the
supersymmetric WZ model defined on the N=1/2 nonanticommutative superspace. By
introducing a spurion field to represent the supersymmetry breaking term F^3 we
are able to perform our calculations using conventional supergraph techniques.
Divergent terms proportional to F, F^2 and F^3 are produced (the first two are
to be expected on general grounds) but no higher-point divergences are found.
By adding ab initio F and F^2 terms to the original lagrangian we render the
model renormalizable. We determine the renormalization constants and beta
functions through two loops, thus making it possible to study the
renormalization group flow of the nonanticommutation parameter.Comment: 36 pages, 25 figures, Latex fil
Projective representation of k-Galilei group
The projective representations of k-Galilei group G_k are found by
contracting the relevant representations of k-Poincare group. The projective
multiplier is found. It is shown that it is not possible to replace the
projective representations of G_k by vector representations of some its
extension.Comment: 15 pages Latex fil
Invertible Dirac operators and handle attachments on manifolds with boundary
For spin manifolds with boundary we consider Riemannian metrics which are
product near the boundary and are such that the corresponding Dirac operator is
invertible when half-infinite cylinders are attached at the boundary. The main
result of this paper is that these properties of a metric can be preserved when
the metric is extended over a handle of codimension at least two attached at
the boundary. Applications of this result include the construction of
non-isotopic metrics with invertible Dirac operator, and a concordance
existence and classification theorem.Comment: Accepted for publication in Journal of Topology and Analysi
q-Deformed Superalgebras
The article deals with q-analogs of the three- and four-dimensional Euclidean
superalgebra and the Poincare superalgebra.Comment: 38 pages, LateX, no figures, corrected typo
Scalar field propagation in the phi^4 kappa-Minkowski model
In this article we use the noncommutative (NC) kappa-Minkowski phi^4 model
based on the kappa-deformed star product, ({*}_h). The action is modified by
expanding up to linear order in the kappa-deformation parameter a, producing an
effective model on commutative spacetime. For the computation of the tadpole
diagram contributions to the scalar field propagation/self-energy, we
anticipate that statistics on the kappa-Minkowski is specifically
kappa-deformed. Thus our prescription in fact represents hybrid approach
between standard quantum field theory (QFT) and NCQFT on the kappa-deformed
Minkowski spacetime, resulting in a kappa-effective model. The propagation is
analyzed in the framework of the two-point Green's function for low,
intermediate, and for the Planckian propagation energies, respectively.
Semiclassical/hybrid behavior of the first order quantum correction do show up
due to the kappa-deformed momentum conservation law. For low energies, the
dependence of the tadpole contribution on the deformation parameter a drops out
completely, while for Planckian energies, it tends to a fixed finite value. The
mass term of the scalar field is shifted and these shifts are very different at
different propagation energies. At the Planckian energies we obtain the
direction dependent kappa-modified dispersion relations. Thus our
kappa-effective model for the massive scalar field shows a birefringence
effect.Comment: 23 pages, 2 figures; To be published in JHEP. Minor typos corrected.
Shorter version of the paper arXiv:1107.236
Combined immune checkpoint inhibitor therapy with nivolumab and ipilimumab causing acute-onset type 1 diabetes mellitus following a single administration: two case reports.
The use of immune checkpoint inhibitor (ICI) therapy is becoming a standard of care for several cancers. Monoclonal antibodies targeting cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed cell death protein 1 (PD-1) or its ligand (PD-L1) cause a broad spectrum of autoimmune adverse events. ICI-induced type 1 diabetes mellitus (T1DM) is extremely rare (< 1%) but potentially life-threatening. It appears to be more common with PD-1 blockade (or combination immunotherapy) than with anti-CTLA-4 therapy, often during the first three to six months of therapy.
We report an acute onset T1DM with severe inaugural diabetic ketoacidosis (DKA) and remarkably elevated Glutamic Acid Decarboxylase antibody (GADA) titres following a single administration of combined ICI therapy with nivolumab (anti-PD-1) and ipilimumab (anti-CTLA-4) in two adult patients with advanced metastatic melanoma. In these cases, the time to diabetes onset was remarkably short (two and five weeks), and one presented with fulminous T1DM in a previous long-standing type 2 diabetes mellitus.
Oncological patients treated with combination therapy of anti-PD-1 and anti-CTLA-4 can develop a particular pattern of T1DM, with very rapid onset within a few weeks after starting ICI therapy, even in the presence of an existing type 2 diabetes. ICI-induced T1DM is a medical emergency in presence of severe inaugural DKA and requires a collaboration between specialists and primary care physicians, as well as patient education, for early diagnosis and supportive care
Two Coupled Harmonic Oscillators on Non-commutative Plane
We investigate a system of two coupled harmonic oscillators on the
non-commutative plane \RR^2_{\theta} by requiring that the spatial coordinates
do not commute. We show that the system can be diagonalized by a suitable
transformation, i.e. a rotation with a mixing angle \alpha. The obtained
eigenstates as well as the eigenvalues depend on the non-commutativity
parameter \theta. Focusing on the ground state wave function before the
transformation, we calculate the density matrix \rho_0(\theta) and find that
its traces {\rm Tr}(\rho_{0}(\theta)) and {\rm Tr}(\rho_0^2(\theta)) are not
affected by the non-commutativity. Evaluating the Wigner function on
\RR^2_{\theta} confirms this. The uncertainty relation is explicitly determined
and found to depend on \theta. For small values of \theta, the relation is
shifted by a \theta^2 term, which can be interpreted as a quantum correction.
The calculated entropy does not change with respect to the normal case. We
consider the limits \alpha=1 and \alpha={\pi\over 2}. In first case, by
identifying \theta to the squared magnetic length, one can recover basic
features of the Hall system.Comment: 15 pages, 1 figur
Latent human traits in the language of social media: An open-vocabulary approach
Over the past century, personality theory and research has successfully identified core sets of characteristics that consistently describe and explain fundamental differences in the way people think, feel and behave. Such characteristics were derived through theory, dictionary analyses, and survey research using explicit self-reports. The availability of social media data spanning millions of users now makes it possible to automatically derive characteristics from behavioral data-language use-at large scale. Taking advantage of linguistic information available through Facebook, we study the process of inferring a new set of potential human traits based on unprompted language use. We subject these new traits to a comprehensive set of evaluations and compare them with a popular five factor model of personality. We find that our language-based trait construct is often more generalizable in that it often predicts non-questionnaire-based outcomes better than questionnaire-based traits (e.g. entities someone likes, income and intelligence quotient), while the factors remain nearly as stable as traditional factors. Our approach suggests a value in new constructs of personality derived from everyday human language use
- …