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. |