Ray-tracing in pseudo-complex General Relativity

Abstract

Motivated by possible observations of the black hole candidate in the center of our galaxy (Gillessen et al., 2012;Eisenhauer et al., 2011) and the galaxy M87 (Doeleman et al., 2009;Falcke et. al, 2012), ray-tracing methods are applied to both standard General Relativity (GR) and a recently proposed extension, the pseudo-complex General Relativity (pc-GR). The correction terms due to the investigated pc-GR model lead to slower orbital motions close to massive objects. Also the concept of an innermost stable circular orbit (ISCO) is modified for the pc-GR model, allowing particles to get closer to the central object for most values of the spin parameter a than in GR. Thus, the accretion disk, surrounding a massive object, is brighter in pc-GR than in GR. Iron Kα emission line profiles are also calculated as those are good observables for regions of strong gravity. Differences between the two theories are pointed out.

On the Doppler effect for light from orbiting sources in Kerr-type metrics

“…In example, the predictions made in Schönenbach et al (2014) can distinguish between General Relativity and pseudo-complex General Relativity (pcGR) in late 2015 when the Event Horizon Telescope(EHT) (Broderick et al 2011;Lu et al 2014) begins to collect data at our Galaxy's nucleus and that of M87. The advent of such high resolution observations, where we can distinguish fine features in emission lines from accretion disks, makes the formula given here important as we move forward in our analysis of the cosmological gravity theory.…”

“…One such example is treated in Radosz et al (2009), analyzing situations in which the Doppler shift factorizes into the kinematic contribution and the general relativistic contribution (in general, these contributions are intricately entangled). Another example where the formula derived in this paper is useful is in the analysis presented by Schönenbach et al (2014), contrasting the predictions of emission from the accretion disks of central galactic nuclei in General Relativity versus pseudo-complex General Relativity.…”

Predictions of the pseudo-complex theory of gravity for EHT observations – I. Observational tests

“…Intensive ray-tracing simulations of accretion onto the Galactic Center have been performed by Schönenbach et al (2014) for both the standard GR and pc-GR theories. Since the gravitational redshift predicted by pc-GR is less than that predicted by standard GR, the emission from pc-GR accretion is typically brighter.…”

“…This prevents gravitational collapse for very large masses (Hess E-mail: bol@mpe.mpg.de et al 2010, 2015). PC-GR predicts that the emission from orbiting matter has different timing characteristics than that which would be predicted by standard GR due to the different values of the gravitational redshift and orbital frequency (Boller & Müller 2013Schönenbach et al 2014).…”

Walter Greiner: In Memoriam

“…In collaboration with P. O. Hess from the National University of Mexico, he addressed again this problem in a series of articles [2][3][4][5] and demonstrated another tantalizing possibility, namely that mass might change the vacuum properties of the space nearby provoking the building up of dark energy, increasing toward smaller distances to the star. This is equivalent to a Casimir effect and the theory has a so-called pseudo-symplectic structure b , a notion treated in one of the contributions of the present proceedings.…”