21 research outputs found
Thin accretion disk signatures of slowly rotating black holes in Ho\v{r}ava gravity
In the present work, we consider the possibility of observationally testing
Ho\v{r}ava gravity by using the accretion disk properties around slowly
rotating black holes of the Kehagias-Sfetsos solution in asymptotically flat
spacetimes. The energy flux, temperature distribution, the emission spectrum as
well as the energy conversion efficiency are obtained, and compared to the
standard slowly rotating general relativistic Kerr solution. Comparing the mass
accretion in a slowly rotating Kehagias-Sfetsos geometry in Ho\v{r}ava gravity
with the one of a slowly rotating Kerr black hole, we verify that the intensity
of the flux emerging from the disk surface is greater for the slowly rotating
Kehagias-Sfetsos solution than for rotating black holes with the same
geometrical mass and accretion rate. We also present the conversion efficiency
of the accreting mass into radiation, and show that the rotating
Kehagias-Sfetsos solution provides a much more efficient engine for the
transformation of the accreting mass into radiation than the Kerr black holes.
Thus, distinct signatures appear in the electromagnetic spectrum, leading to
the possibility of directly testing Ho\v{r}ava gravity models by using
astrophysical observations of the emission spectra from accretion disks.Comment: 12 pages, 15 figures. V2: 13 pages, clarifications and discussion
added; version accepted for publication in Classical and Quantum Gravit
The NSVZ β-function and the Schwinger-Dyson equations for N = 1 SQED with N f flavors, regularized by higher derivatives
One-loop divergences in non-Abelian supersymmetric theories regularized by BRST-invariant version of the higher derivative regularization
Sub-Terahertz Frequency-Domain Spectroscopy Reveals Single-Grain Mobility and Scatter Influence of Large-Area Graphene
Synthesis of novel 1,4-naphthoquinone derivatives: antibacterial and antifungal agents
A novel series of substituted 1,4-naphthoquinone derivatives was synthesized and evaluated for antibacterial and antifungal activity. The structures of the novel products were characterized by spectroscopic methods. Among the tested compounds, 3a and 9 are the most effective compounds against M. luteum as potent antibacterial and C. tenuis and A. niger as potent antifungal. These two compounds are promising as biologically active compounds