787 research outputs found
Local normal forms for c-projectively equivalent metrics and proof of the Yano-Obata conjecture in arbitrary signature. Proof of the projective Lichnerowicz conjecture for Lorentzian metrics
Two K\"ahler metrics on a complex manifold are called c-projectively
equivalent if their -planar curves coincide. These curves are defined by the
property that the acceleration is complex proportional to the velocity. We give
an explicit local description of all pairs of c-projectively equivalent
K\"ahler metrics of arbitrary signature and use this description to prove the
classical Yano-Obata conjecture: we show that on a closed connected K\"ahler
manifold of arbitrary signature, any c-projective vector field is an affine
vector field unless the manifold is with (a multiple of) the
Fubini-Study metric. As a by-product, we prove the projective Lichnerowicz
conjecture for metrics of Lorentzian signature: we show that on a closed
connected Lorentzian manifold, any projective vector field is an affine vector
field.Comment: comments are welcom
Two remarks on -projectivity of Riemannian metrics
We show that -projectivity of two Riemannian metrics
introduced in \cite{Top2003} implies affine equivalence of the metrics unless
. Moreover, we show that for ,
-projectivity implies projective equivalence.Comment: 6 pages, 2 figure
New regulation for clinical stem cell research in China: expected impact and challenges for implementation
On August 22, 2015 the Chinese National Health and Family Planning Commission (NHFPC, the former Ministry of Health, MOH) have issued the long awaited “draft” regulation on clinical research and applications that involve human stem cells [1] [2] [3]. In China, regulation usually starts out as a draft (草案) or trial regulation (试行). A draft regulation should be regarded as valid as formal regulation, but it is flexible enough to leave space for change. The document announces the central elements of a regulatory foundation for the clinical translation of stem cell-based medicinal products and procedures. What does China’s future regulation for clinical stem cell trials look like? What challenges can be expected with regard to its implementation? And what impacts will the regulation have for domestic researchers, clinics and corporations in China and at an international level
Local normal forms for c-projectively equivalent metrics and proof of the Yano-Obata conjecture in arbitrary signature. Proof of the projective Lichnerowicz conjecture for Lorentzian metrics
Two Kähler metrics on a complex manifold are called c-projectively equivalent if their -planar curves coincide. These curves are defined by the property that the acceleration is complex proportional to the velocity. We give an explicit local description of all pairs of c-projectively equivalent Kähler metrics of arbitrary signature and use this description to prove the classical Yano-Obata conjecture: we show that on a closed connected Kähler manifold of arbitrary signature, any c-projective vector field is an affine vector field unless the manifold is CPn with (a multiple of) the Fubini-Study metric. As a by-product, we prove the projective Lichnerowicz conjecture for metrics of Lorentzian signature: we show that on a closed connected Lorentzian manifold, any projective vector field is an affine vector field
ProMoEE - A lightweight web editor supporting study research on process models
Process models are not only used for the sole documentation of the numerous processes in an organization. Among others, they are essential artifacts in the context of service-oriented computing. Hence, high quality process models are the enabler for streamlining, prediction, and automation in many fields (e.g., industrial production). Therefore, a proper and effective comprehension of process models and knowledge about factors influencing the creation of such models constitutes a key criterion for this endeavor. The collection and analysis of data in scientific studies help to understand the objective and subjective factors influencing process model creation and comprehension. This work presents an editor for the definition, execution, and analysis of studies in the context of process model creation and comprehension. The editor features a clean design and allows for a fast implementation for conducting and reporting study research, while ensuring the collection of high-quality data
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