Results 11 to 20 of about 2,217,119 (170)

On black holes in string theory [PDF]

open access: yes, 2011
PhDThis thesis investigates black holes in string theory through string amplitudes and through gauge-gravity duality. The research presented in this thesis supports the claim that string theory is capable of a consistent quantum-mechanical description
Turton, David J, Turton, David J.
core   +4 more sources

The Brightest Point in Accretion Disk and Black Hole Spin: Implication to the Image of Black Hole M87*

open access: yesUniverse, 2019
We propose the simple new method for extracting the value of the black hole spin from the direct high-resolution image of black hole by using a thin accretion disk model.
Vyacheslav I. Dokuchaev   +1 more
doaj   +1 more source

PAWS and POCO: NIR Astrophotonic Instruments for Astronomy

open access: yesAstronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023
Abstract For near‐infrared ground and space‐based astronomy, compact photonic devices can replace the large bulk optical components in spectrographs, frequency combs, beam combiners, and sky subtraction filters, thus saving cost, reducing volume, weight, and power requirements.
Kalaga Madhav   +8 more
wiley   +1 more source

Shadow of a rotating squashed Kaluza-Klein black hole

open access: yesJournal of High Energy Physics, 2019
We study the shadow of a rotating squashed Kaluza-Klein (KK) black hole and the shadow is found to possess distinct properties from those of usual rotating black holes.
Fen Long   +3 more
doaj   +1 more source

Shadow of rotating and twisting charged black holes with cloud of strings and quintessence

open access: yesEuropean Physical Journal C: Particles and Fields, 2023
Testing gravity theories is an important and interesting issue in relativistic astrophysics using astrophysical observations. In recent years, Event horizon telescope collaboration provided valuable data from shadow of supermassive black holes located at
Muhammad Zahid   +4 more
doaj   +1 more source

Characterization of a C‐RED One camera for astrophotonical applications

open access: yesAstronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023
Abstract To better understand the impact of the avalanche gain applied in the detector technology and apply this technology in our in‐house astrophotonic projects, we have characterized a C‐RED One camera and produced a stable and reliable method for calculating the system gain at any desired avalanche gain setting.
Stella Vješnica   +3 more
wiley   +1 more source

Mass Functions of Supermassive Black Holes across Cosmic Time

open access: yesAdvances in Astronomy, 2012
The black hole mass function of supermassive black holes describes the evolution of the distribution of black hole mass. It is one of the primary empirical tools available for mapping the growth of supermassive black holes and for constraining ...
Brandon C. Kelly, Andrea Merloni
doaj   +1 more source

A Global Inventory of Feedback

open access: yesGalaxies, 2023
Feedback from both supermassive black holes and massive stars plays a fundamental role in the evolution of galaxies and the inter-galactic medium. In this paper, we use available data to estimate the total amount of kinetic energy and momentum created ...
Timothy M. Heckman, Philip N. Best
doaj   +1 more source

The NANOGrav 12.5 yr Data Set: Bayesian Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries

open access: yesThe Astrophysical Journal Letters, 2023
Pulsar timing array collaborations, such as the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), are seeking to detect nanohertz gravitational waves emitted by supermassive black hole binaries formed in the aftermath of galaxy ...
Zaven Arzoumanian   +78 more
doaj   +1 more source

Quantum Aspects of Black Holes [PDF]

open access: yes, 2006
In this thesis we study two quantum aspects of black holes, their entropy and the Hawking effect. First, we present a model for the statistical interpretation of black hole entropy and show that this entropy emerges as a result of missing information ...
Deeg, Dorothea
core   +1 more source

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