Search FQXi


If you are aware of an interesting new academic paper (that has been published in a peer-reviewed journal or has appeared on the arXiv), a conference talk (at an official professional scientific meeting), an external blog post (by a professional scientist) or a news item (in the mainstream news media), which you think might make an interesting topic for an FQXi blog post, then please contact us at forums@fqxi.org with a link to the original source and a sentence about why you think that the work is worthy of discussion. Please note that we receive many such suggestions and while we endeavour to respond to them, we may not be able to reply to all suggestions.

Please also note that we do not accept unsolicited posts and we cannot review, or open new threads for, unsolicited articles or papers. Requests to review or post such materials will not be answered. If you have your own novel physics theory or model, which you would like to post for further discussion among then FQXi community, then please add them directly to the "Alternative Models of Reality" thread, or to the "Alternative Models of Cosmology" thread. Thank you.

Forum Home
Introduction
Terms of Use

Order posts by:
 chronological order
 most recent first

Posts by the blogger are highlighted in orange; posts by FQXi Members are highlighted in blue.

By using the FQXi Forum, you acknowledge reading and agree to abide by the Terms of Use

 RSS feed | RSS help
RECENT POSTS IN THIS TOPIC

Zeeya Merali: on 5/21/22 at 15:26pm UTC, wrote İzzet Sakallı of Eastern Mediterranean University in Northern Cyprus and...


RECENT FORUM POSTS

Steve Dufourny: "This platform is about theoretical physics, it is irritating to have these..." in 16th Marcel Grossmann...

Steve Dufourny: "post under review , irritating" in 16th Marcel Grossmann...

Steve Dufourny: "I recommand this you tube of Professor Ellis about mind, intelligence,..." in George Ellis - How can...

Steve Dufourny: "irritating these posts, they shall disappear simply because under review..." in George Ellis - How can...

Steve Dufourny: "I have thought about this theory of wave pilot and the wave particle..." in The Noise of Gravitons

Steve Dufourny: "That becomes interesting now to consider so these series finite of 3D..." in The Noise of Gravitons

Steve Dufourny: "I have a dream , like you know I have conviced FQXi to create the forum..." in Global Collaboration

Steve Dufourny: "Let s try please dear members of FQXi, let s forget our vanity, lets forget..." in Global Collaboration


RECENT ARTICLES
click titles to read articles

The Math of Consciousness: Q&A with Kobi Kremnitzer
A meditating mathematician is developing a theory of conscious experience to help understand the boundary between the quantum and classical world.

Can We Feel What It’s Like to Be Quantum?
Underground experiments in the heart of the Italian mountains are testing the links between consciousness and collapse theories of quantum physics.

The Thermodynamic Limits of Intelligence: Q&A with David Wolpert
Calculating the energy needed to acquire and compute information could help explain the (in)efficiency of human brains and guide the search for extra-terrestrial intelligence.

Gambling Against the Second Law
Using precision thermometry to make mini heat engines, that might, momentarily, bust through the thermodynamic limit.

Mind and Machine: What Does It Mean to Be Sentient?
Using neural networks to test definitions of 'autonomy.'


FQXi BLOGS
June 29, 2022

CATEGORY: Blog [back]
TOPIC: Fingerprints of Invisibles [refresh]
Bookmark and Share
Login or create account to post reply or comment.

FQXi Administrator Zeeya Merali wrote on May. 21, 2022 @ 15:26 GMT
İzzet Sakallı of Eastern Mediterranean University in Northern Cyprus and Sara Kanzi of Final International University have published a topical review article, "Greybody Factors and Quasinormal Modes for Black Holes in Various Theories – Fingerprints of Invisibles" in the Turkish Journal of Physics, a scientific journal of Scientific And Technological Research Council Of Turkey, (Turk J Phys (2022) 46: 51 – 103 © TUBİTAK https://doi.org/10.55730/1300-0101.2691, arXiv preprint (2022).)

From İzzet Sakallı:

Black holes, a generic prediction of Einstein’s General Relativity, are objects of paramount importance both for classical and quantum gravity. Greybody factors and quasinormal modes are two topics related to black hole physics of particular interest. On the one hand, Hawking since it is as a manifestation of a quantum effect in curved spacetime, has always attracted a lot of interest although it has not been detected in the Universe yet. The emitted particles feel an effective potential that back scatters part of the emitted radiation back into the black hole. The greybody factor is a frequency dependent quantity that measures the deviation from the original black body radiation spectrum and provides us with valuable information about the black hole horizon structure. On the other hand, LIGO historical direct detection of gravitational waves from black hole mergers has opened a completely new window to our Universe and allows us to test gravity and probe strong gravitational fields. Consequently, lately there is an increasing interest in black hole perturbations and quasinormal modes of black holes, intimately related to the ring down phase after the formation of the distorted object during the merging of two black holes. When a black hole is perturbed the geometry of spacetime undergoes dumped oscillations, which are characterized by the quasinormal modes with a non-vanishing imaginary part. Chandrasekhar’s famous monograph “The Mathematical Theory of Black Holes” provides us with a comprehensive overview of black hole perturbations.

The study, published April 28 in the Turkish Journal of Physics (doi:10.3906/fiz-2203-15), reviewed the various analytical and numerical methodologies to derive the greybody factors and quasinormal modes of the black holes and black hole like curved spacetimes. The physicists gave specific examples about how one can compute the greybody factors and quasinormal modes. Theoretical findings are also linked to current and possible future observational physics. Stating that it will be a good resource for all physicists interested in these issues, the authors also said that they are going to update their work over the years.

One of the greybody factor results is shown in the figure below:



Bookmark and Share
this post has been edited by the forum administrator



Login or create account to post reply or comment.

Please enter your e-mail address:
Note: Joining the FQXi mailing list does not give you a login account or constitute membership in the organization.