ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 37 (1996), S. 4557-4573 
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: Static spherically symmetric uncoupled scalar space–times have no event horizon and a divergent Kretschmann singularity at the origin of the coordinates. The singularity is always present so that nonstatic solutions have been sought to see if the singularities can develop from an initially singular free space–time. In flat space–time the Klein–Gordon equation (D'Alembertian)cursive-phi=0 has the nonstatic spherically symmetric solution cursive-phi=σ(v)/r, where σ(v) is a once differentiable function of the null coordinate v. In particular, the function σ(v) can be taken to be initially zero and then grow, thus producing a singularity in the scalar field. A similar situation occurs when the scalar field is coupled to gravity via Einstein's equations; the solution also develops a divergent Kretschmann invariant singularity, but it has no overall energy. To overcome this, Bekenstein's theorems are applied to give two corresponding conformally coupled solutions. One of these has positive ADM mass and has the following properties: (i) it develops a Kretschmann invariant singularity, (ii) it has no event horizon, (iii) it has a well-defined source, (iv) it has well-defined junction condition to Minkowski space–time, and (v) it is asymptotically flat with positive overall energy. This paper presents this solution and several other nonstatic scalar solutions. The properties of these solutions which are studied are limited to the following three: (i) whether the solution can be joined to Minkowski space–time, (ii) whether the solution is asymptotically flat, (iii) and, if so, what the solutions' Bondi and ADM masses are. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    General relativity and gravitation 20 (1988), S. 775-792 
    ISSN: 1572-9532
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The Bel-Robinson tensor is the most used gravitational energy tensor; however, it has the dimensions of energy squared. How to construct tensors with the dimensions of energy by using Lancoz tensors is shown here. The resulting tensors have a large number of arbitrary parameters, frequently have spacelike currents, and frequently do not reduce to familiar pseudo-energy tensors in the weak field limit. Two particular examples of interest are one with well-behaved currents and one which reduces to an energy pseudo-tensor in the weak field limit.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    General relativity and gravitation 21 (1989), S. 907-939 
    ISSN: 1572-9532
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The applications of spherically symmetric solutions of the massless scalar Einstein equations to cosmic censorship are discussed. A new nonstatic solution to these equations is given. The Vaidya form of Wyman's solution is constructed and is shown to obey reasonable energy conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    General relativity and gravitation 17 (1985), S. 913-926 
    ISSN: 1572-9532
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that the solution of the field equations for a static spherically symmetric scalar field has a scalar polynomial singularity and no event horizon. The solution does not develop from nonsingular data on any Cauchy surface. The possible existence of a universal scalar field, the conformal diagram and geodesies of the solution, and the energy and momentum of the field present are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Czechoslovak journal of physics 42 (1992), S. 151-158 
    ISSN: 1572-9486
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that: i) the Weyl tensor can be expressed in terms of the sum of a tensor and its double dual, where the tensor is constructed from the covariant derivatives of the Lanczos tensor, ii) a similar expression does not exist for the Riemann tensor in electromagnetic theory, iii) the electromagnetic field cannot be identified with the differential gauge freedom of the Lanczos tensor, iv) the symmetries of Einstein Maxwell theory and the Lanczos tensor do not prohibit the identification of the electromagnetic field with the algebraic gauge freedom of the Lanczos tensor, these symmetries require a differential equation relating the electromagnetic field tensor to the algebraic gauge vector and this is given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1572-9508
    Keywords: atmospheric ; Čerenk technique ; gamma ray astronomy ; gamma ray telescopes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The design, construction and operation of the University of Durham ground-based gamma ray telescope is discussed. The telescope has been designed to detect gamma rays in the ≤ 200 GeV region and to achieve good discrimination between gamma ray and hadron initiated showers in the higher energy region (≳ 300 GeV). The telescope was commissioned in 1995 and a description of its design and operation is presented, together with a verification of the telescope's performance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1572-9672
    Keywords: VHE gamma ray astronomy ; gamma ray telescopes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Current approaches to the identification of VHE gamma rays using stereo images of Čerenkov light flashes are reviewed. The method of analysis developed by the University of Durham group involving a measure of cascade development is described. This method is applied to observations of a burst of VHE gamma rays from AE Aqr and enhancement of the gamma ray signal is demonstrated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    General relativity and gravitation 28 (1996), S. 1385-1392 
    ISSN: 1572-9532
    Keywords: Generalized Klein-Gordon equation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract There exists a two parameter action, the variation of which produces both the geodesic equation and the geodesic deviation equation. In this paper it is shown that this action can be quantized by the canonical method, resulting in equations which generalize the Klein-Gordon equation. The resulting equations might have applications, and also show that entirely unexpected systems can be quantized. The possible applications of quantized geodesic deviation are to i) the spreading wave packet in quantum theory, and ii) the one-particle-to-many-particle problem in second quantized quantum field theory.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Mathematical physics, analysis and geometry 1 (1998), S. 367-374 
    ISSN: 1572-9656
    Keywords: quantum commutator algebra ; perfect fluid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract A perfect fluid is quantized by the canonical method. The constraints are found and this allows the Dirac brackets to be calculated. Replacing the Dirac brackets with quantum commutators formally quantizes the system. There is a momentum operator in the denominator of some coordinate quantum commutators. It is shown that it is possible to multiply throughout by this momentum operator. Factor ordering differences can result in a viscosity term. The resulting quantum commutator algebra is unusual.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Astrophysics and space science 147 (1988), S. 321-327 
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Wyman's solution is the most general solution to the static spherically-symmetric Einstein massless scalar field equations. It is shown that it has no axial perturbation in which the scalar field is incremented, except in the case where the initial scalar field and the cross-metric increments are negligible. The one dimensional Schrödinger equation which governs axial metrix perturbations is produced.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...