Department of Relativistic Astrophysics and Cosmology
 
 
Selected publications
 
   
   
   
    from to   type  
  res per page (102 res)  

[<] [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [>] [>>]

43. Agnieszka Uczyńska - wywiad z Sebastianem J. Szybka
Kosmiczne laboratorium fizyków
Nauka w Polsce - serwis PAP (2007).
[abstract] [journal]

Abstract:
Wywiad dla Polskie Agencji Prasowej - serwis Nauka w Polsce.

44. Agnieszka Uczyńska - wywiad z Sebastianem J. Szybka
Osobliwości - patologie czasu i przestrzeni
Nauka W Polsce - serwis PAP (2007).
[abstract] [journal]

Abstract:
Wywiad dla Polskiej Agencji Prasowej - serwis Nauka w Polsce.

45. Agnieszka Uczyńska - wywiad z Sebastianem J. Szybka
Tajemnice ciemnej energii
Nauka w Polsce - serwis PAP (2007).
[abstract] [journal]

Abstract:
Wywiad dla Polskiej Agencji Prasowej - serwis Nauka w Polsce.

46. Artur Janda
Spherically Symmetric Solutions of the Einstein--Bach Equations and a Consistent Spin-2 Field Theory
Acta Phys. Pol., B , vol. B37/12, pp. 3667-3678 (2006).
[abstract] [preprint] [journal] [download]

Abstract:
We briefly present a relationship between General Relativity coupled to certain spin-0 and spin-2 field theories and higher derivatives metric theories of gravity. In a special case, described by the Einstein--Bach equations, the spin-0 field drops out from the theory and we obtain a consistent spin-two field theory interacting gravitationally, which overcomes a well known inconsistency of the theory for a linear spin-two field coupled to the Einstein's gravity. Then we discuss basic properties of static spherically symmetric solutions of the Einstein--Bach equations.

47. Leszek M. Sokołowski, Andrzej Staruszkiewicz
On the issue of gravitons
Class. Quant. Grav. , vol. 23, pp. 5907-5918 (2006).
[abstract] [preprint] [journal]

Abstract:
We investigate the problem of whether one can anticipate any features of the graviton without a detailed knowledge of a full quantum gravity. Assuming that in linearized gravity the graviton is in a sense similar to the photon, we derive a curious large number coincidence between the number of gravitons emitted by a solar planet during its orbital period and the number of its nucleons. In Einstein's GR the analogy between the graviton and the photon is ill founded. A generic relationship between quanta of a quantum field and plane waves of the corresponding classical field is broken in the case of GR. The graviton cannot be classically approximated by a generic pp wave nor by the exact plane wave. Most important, the ADM energy is a zero frequency characteristic of any asymptotically flat spacetime and this means that any general relationship between energy and frequency is a priori impossible. In particular the formula $E=\hbar \omega$ does not hold. The graviton must have features different from those of the photon and these cannot be predicted from classical general relativity.

48. P. T. Chrusciel, G. M. Greuel, R. Meinel, S. J. Szybka
The Ernst equation and ergosurfaces
Class. Quantum Grav., vol. 23, pp. 4399-4414 (2006).
[abstract] [preprint] [journal]

Abstract:
We show that analytic solutions $\mcE$ of the Ernst equation with non-empty zero-level-set of $\Re \mcE$ lead to smooth ergosurfaces in space-time. In fact, the space-time metric is smooth near a "Ernst ergosurface" $E_f$ if and only if $\mcE$ is smooth near $E_f$ and does not have zeros of infinite order there.

[<] [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [>] [>>]