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1.
This is a summary of the papers presented in session W1 on the papers submitted to the workshop I on the classical aspects of black holes and compact objects were classified into three categories: (i) theoretical aspects; (ii) astrophysical aspects; (iii) gravitational radiation. The three sessions were devoted each to one of the above categories. The chairmen of the workshop were J Bičák, Charles University, Prague (Czech Republic) and C V Vishveshwara, Indian Institute of Astrophysics, India.  相似文献   

2.
Papers presented in the second workshop are briefly reviewed. The 1+3 covariant approach to microwave background anisotropies and structure formation was well represented. Other topics included gravitational lensing and caustics, alternative approaches to galactic observations, conserved quantities in perturbation theory and primordial black holes.  相似文献   

3.

A workshop on Engineering Applications of Neutrons and Synchrotron Radiation took place on September 13–14, 2004, at the ESRF in Grenoble, France. The workshop brought together around 100 leading scientists and engineers who discussed the application of synchrotron X-ray and neutron central facilities for engineering problems. The event was organized by the FaME38 materials engineering facility at ILL-ESRF. FaME38 is jointly funded by the UK research council EPSRC and ILL-ESRF and provides support to enable materials engineers to make the best use of the advanced synchrotron X-ray and neutron scientific facilities at ILL-ESRF.

The programme included formal presentations, a poster session, informal workgroup sessions and an opportunity to meet staff at the ILL-ESRF materials science beamlines. The formal presentations were structured into three sessions entitled Progress, Complementarity, and Applications chaired by Giovanni Bruno (ILL), Thomas Buslaps (ESRF), and Darren Hughes (FaME38).  相似文献   

4.
The Institute of High Energy Physics of Chinese Academy of Sciences organized a workshop to establish closer contacts between experimentalists (theorists) involved in the studies of charm physics from both c and B communities. The workshop covers talks of physics analysis and its results from four electron-positron colliding experiments (BES, Belle, CLEO and BaBar). Presentations at the workshop are organized in the following sessions : (1) Hadron spectroscopy and new resonances; (2) D0-D0 mixing; (3) Charmonium decays; (4) Charm hadronic and (semi-)lcptonic decays; (5) QCD at low energy and τphysics; (6) Partial wave analysis and Dalitz analysis, MC generator and Tools; (7) Detector upgrade.  相似文献   

5.
Four workshops were held on November 18, 2005, prior to the plenary Users' Meeting. The sessions were well attended and featured topics of interest both to veteran synchrotron users and interested workers from a variety of disciplines, ranging from archeology and accelerator physics to plant sciences and “extreme imaging.” A one-day workshop was devoted to future single-bunch operation at the CLS. The workshop's mandate was twofold. One aim was to gauge the interest of the user community for a single bunch mode of operation, including specific requirements such as the bunch current and the bunch purity.  相似文献   

6.
The Fifth SOLEIL Users' Meeting, attended by no less than 344 participants from 11 countries, took place on January 20–21, 2010, at the Ecole Polytechnique (Palaiseau) for the six plenary lectures (Photo 1) and parallel sessions, and at SOLEIL for the poster session and the commercial exhibition. Prior to the main meeting, a satellite workshop was organized on January 18–19 in the field of high-energy photoemission spectroscopy (HAXPES) in relation to the new future GALAXIES beamline.  相似文献   

7.
A non-geometric relativistic theory of gravitation is developed by defining a semi-metric to replace the metric tensor as gravitational vector potential. The theory show that the energy-momentum tensor of the gravitational field belong to the gravitational source, gravitational radiation is contained in Einstein’s field equations that including the contribution of gravitational field, the real physical singularity in the gravitational field can be eliminated, and the dark matter in the universe is interpreted as the matter of pure gravitational field.  相似文献   

8.
On September 19-21, 2005, the Synchrotron Environmental Science III (SES-III) conference was held at Brookhaven National Laboratory (BNL), in Upton, New York. Continuing the tradition established by previous SES conferences held at Argonne National Lab, SES-III brought together the diverse community of scientists who apply synchrotron-based radiation techniques to study the biological and geochemical aspects of both local and global environmental issues. The conference included two days of topical sessions that addressed the application of innovative synchrotron methods in environmental science along with applications in bioavailability and remediation science. The third day included a workshop on microbeam methods. Attendees reported on environmental science activities conducted at synchrotron facilities worldwide.  相似文献   

9.
WU Ning 《理论物理通讯》2005,44(5):883-886
In quantum gauge theory of gravity, the gravitational field is represented by gravitational gauge field. The field strength of gravitational gauge field has both gravitoelectric component and gravitomagnetic component. In classical level, gauge theory of gravity gives classical Newtonian gravitational interactions in a relativistic form. Besides, it gives gravitational Lorentz force, which is the gravitational force on a moving object in gravitomagnetic field. The direction of gravitational Lorentz force is not the same as that of classical gravitational Newtonian force. Effects of gravitational Lorentz force should be detectable, and these effects can be used to discriminate gravitomagnetic field from ordinary electromagnetic magnetic field.  相似文献   

10.
In quantum gauge theory of gravity, the gravitational field is represented by gravitational gauge field.The field strength of gravitational gauge field has both gravitoelectric component and gravitomagnetic component. In classical level, gauge theory of gravity gives classical Newtonian gravitational interactions in a relativistic form. Besides,it gives gravitational Lorentz force, which is the gravitational force on a moving object in gravitomagnetic field The direction of gravitational Lorentz force is not the same as that of classical gravitational Newtonian force. Effects of gravitational Lorentz force should be detectable, and these effects can be used to discriminate gravitomagnetic field from ordinary electromagnetic magnetic field.  相似文献   

11.
A Yang-Mills formulation of Einstein gravity with spin-affine connection as the dynamical variable of gravitational field is suggested based on the Stephenson-Kilmister-Yang (SKY) equation. A physically interesting property of the present formalism is that the Einstein field equation appears as a first-integral solution to the Yang-Mills type gravitational gauge field equation. The gravitational current density, the law of conservation and the gravitational gauge field strength in vierbein formulation are discussed. The present scheme could provide us with new insight into a possible way to include both Yang-Mills field and gravitational gauge field into one framework of generalized vierbein fields.  相似文献   

12.
The fourth in a series of workshops devoted to the use of diamonds at synchrotrons and free electron lasers (FELs) was held on May 5-6, 2011, at the Advanced Photon Source. The previous DMSL workshop was held in Japan in 2008. The workshop was supported in part by Argonne National Laboratory; Applied Diamond, Inc.; SINMAT, Inc.; and elementsix, Ltd. The scope was to assess : 1) the status, size, quality, and availability of synthetic type IIa diamonds; 2) the status of CVD diamonds; 3) applications for beamline optics; 4) applications for beam position monitors (BPMs) and detectors; 5) applications at FELs; and 6) novel applications, such as for an X-ray free electron laser oscillator (XFELO). On May 5, Linda Young (APS/XSD) gave the workshop welcome. There were three sessions on each of the two days. A website was created and will be kept live where the detailed age-nda and list of speakers will remain available (http://www.aps.anl.gov/News/Conferences/2011/DMLS). As part of the session on BPMs and detectors, there were several speakers from outside the light source community, which demonstrated that there is a larger science audience for these applications than just light sources. Highlights of the workshop include: 1) reports of supplier facilities for thinning and polishing; 2) reports on tests of supplier-provided bonds to CVD cooling manifolds; 3) a report of more than 99% reflectivity from diamond for hard X-rays, significant for XFELO feasibility, measured at the APS; 4) a report on thermal expansion measurements at low temperatures made at the APS (no negative thermal expansion, thermal expansion below 1e-9); 5) a report from Brookhaven National Laboratory on substantial progress in diamond beam flux monitors (BPMs), and fast detectors; 6) a presentation on plans for a self-seeding at LCLS with diamond crystals. A synopsis of each technical session follows below.  相似文献   

13.
The quasinormal modes of the Schwarzschild black hole surrounded by the quintessence in Rastall gravity are studied using the sixth-order Wentzel-Kramers-Brillouin approximative approach. The effect of the Rastall parameter on the quasinormal modes of gravitational, electromagnetic and massless scalar perturbations is explored. Compared to the case of Einstein gravity, it is found that, when η < 0, the gravitational field, electromagnetic field as well as massless scalar field damp more rapidly and have larger real frequency of oscillation in Rastall gravity, while when η > 0, the gravitational field, electromagnetic field as well as massless scalar field damp more slowly and have smaller real frequency of oscillation in Rastall gravity. It is also found that the gravitational field, electromagnetic field as well as massless scalar field damp more and more slowly and the real frequency of oscillation for the gravitational perturbation, electromagnetic perturbation as well as massless scalar perturbation becomes smaller and smaller as the Rastall parameter η increases. Compared among the quasinormal frequencies of gravitational, electromagnetic and massless scalar perturbations, I find that, for fixed η, (l, n), ∈ and Nq, the oscillation damps most slowly for the gravitational perturbation, mediate for the electromagnetic perturbation and most rapidly for the massless scalar perturbation, and the real frequency of oscillation is the smallest for the gravitational perturbation, mediate for the electromagnetic perturbation and the largest for the massless scalar perturbation in Rastall gravity.  相似文献   

14.
We define passive gravitational mass operator of a hydrogen atom in the post-Newtonian approximation of general relativity and show that it does not commute with energy operator, taken in the absence of gravitational field. Nevertheless, the equivalence between the expectation values of passive gravitational mass and energy is shown to survive for stationary quantum states. Inequivalence between passive gravitational mass and energy at a macroscopic level results in time dependent oscillations of the expectation values of passive gravitational mass for superpositions of stationary quantum states, where the equivalence restores after averaging over time. Inequivalence between gravitational mass and energy at a microscopic level reveals itself as unusual electromagnetic radiation, emitted by the atoms, supported and moved in the Earth gravitational field with constant velocity using spacecraft or satellite, which can be experimentally measured.  相似文献   

15.
We study gravitational properties of vacuum energy by erecting a geometry on the stress-energy tensor of vacuum, matter and radiation. Postulating that the gravitational effects of matter and radiation can be formulated by an appropriate modification of the spacetime connection, we obtain varied geometrodynamical equations which properly comprise the usual gravitational field equations with, however, Planck-suppressed, non-local, higher-dimensional additional terms. The prime novelty brought about by the formalism is that, the vacuum energy does act not as the cosmological constant but as the source of the gravitational constant. The formalism thus deafens the cosmological constant problem by channeling vacuum energy to gravitational constant. Nevertheless, quantum gravitational effects, if any, restore the problem via the graviton and graviton-matter loops, and the mechanism proposed here falls short of taming such contributions to cosmological constant.  相似文献   

16.
The deflection of light rays by rotating gravitational lens is considered in the framework of higher-order gravitational theory. The bending angle of light is derived. The effect of the massive scalar and tensor components of higher-order gravitational field as well as the gravito-magnetic on light deflection are discussed.  相似文献   

17.
空间引力波探测计划-LISA系统设计要点   总被引:2,自引:0,他引:2       下载免费PDF全文
王智  马军  李静秋 《中国光学》2015,8(6):980-987
为了验证广义相对论,世界各国竞相开展了空间引力波探测方面的研究。本文以欧洲空间引力波探测LISA(Laser Interferometer Space Antenna)计划为例,根据基线设计,对LISA系统有效载荷及主要组件的设计进行了分析和阐述。LISA主要探测和研究低频引力波辐射,其工作频段为10-3~1 Hz,工作距离为5×106 km,预计能探测到双致密星系统以及星系合并引起的超大质量并合等波源,测距精度达到pm量级。以上研究希望能对我国未来的空间引力波探测计划有一定启示。  相似文献   

18.
The Canadian Light Source (CLS) is Canada's national synchrotron radiation facility. The CLS mission statement includes a mandate to “participate actively in educational, social and cultural development of our communities.” Over 6,000 people annually, more than half of them school children, tour the CLS. This is facilitated by the design of the building, which has a mezzanine affording panoramic views of the accelerators and experimental floor (see Figure 1). CLS staff have presented to more than a thousand educators through various professional development sessions, and for these educators classroom resource material is made available for easy inclusion in daily lessons where possible. The CLS also hosts an annual workshop for teachers where, since 2006, more than one hundred teachers have spent several days at CLS becoming familiar with the facility.  相似文献   

19.
The Lagrangian based theory of the gravitational field and its sources at the arbitrary background space-time is developed. The equations of motion and the energy-momentum tensor of the gravitational field are derived by applying the variational principle. The gauge symmetries of the theory and the associated conservation laws are investigated. Some properties of the energymomentum tensor of the gravitational field are described in detail and the examples of its application are given. The desire to have the total energymomentum tensor as a source for the linear part of the gravitational field leads to the universal coupling of gravity with other fields (as well as to the self-interaction) and finally to the Einstein theory.  相似文献   

20.
I describe how gravitational entropy is intimately connected with the concept of gravitational heat, expressed as the difference between the total and free energies of a given gravitational system. From this perspective one can compute these thermodyanmic quantities in settings that go considerably beyond Bekenstein's original insight that the area of a black hole event horizon can be identified with thermodynamic entropy. The settings include the outsides of cosmological horizons and spacetimes with NUT charge. However the interpretation of gravitational entropy in these broader contexts remains to be understood.  相似文献   

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