A METHOD TO TEST THE EXISTENCE OF REGULAR BLACK HOLES

Illustration of a black hole. Image Credit & Copyright: Alain Riazuelo

The existence of the singularity is an intrinsic problem of the General Relativity (GR).

At the fundamentally level, the resolution of the problem of the singularity lies with the expectation that under situations where quantum effects become strong, the behavior of gravity could possibly greatly deviate from that predicted by the classical theory of GR.

Regular black hole solution are proposed with the same spacetime geometry outside the horizon as the traditional black hole, but bears no singularity inside. Whether or not black hole singularities should exist, they would be covered by the black hole horizon. The black hole horizon serves as an information curtain hindering outside observers from directly observing the interior structure of the black hole, and determining that whether or not the black hole singularity does really exist.

A method is needed to check the correctness of the new constructions of regular black holes. In a recent paper (Deng & Cleaver 2016) the authors suggest to use the Hawking radiation as a possible method to probe into the structure of black holes.

Mechanism of the Hawking radiation near the event horizon.

Hawking radiation is black-body radiation that is predicted to be released by black holes, due to quantum effects near the event horizon.

The authors study the Hawking radiation through fermion tunnelling from one type regular black hole. They assess that results contain modifications from that of the traditional black hole, which confirms the possibility of employing the Hawking radiation as a promising method to probe into the structure of black holes as far as these modifications are testable at astronomical observations.

Deng & Cleaver 2016 - Hawking Radiation from Regular Black Hole as a Possible Probe for Black Hole Interior Structure (arXiv)
Hawking radiation - (Wikipedia)

Comments

Forest of Molecular Signals in Star Forming Galaxy

Spiral Galaxy NGC 253. Credit: ESO Astronomers found a rich molecular reservoir in the heart of an active star-forming galaxy with the Atacama Large Millimeter/submillimeter Array (ALMA). Among eight clouds identified at the center of the galaxy NGC 253, one exhibits very complex chemical composition, while in the other clouds many signals are missing. This chemical richness and diversity shed light on the nature of the baby boom galaxy. Ryo Ando, a graduate student of the University of Tokyo, and his colleagues observed the galaxy NGC 253 and for the first time, they resolved the locations of star formation in this galaxy down to the scale of a molecular cloud, which is a star formation site with a size of about 30 light-years. As a result, they identified eight massive, dusty clouds aligned along the center of the galaxy. “With its unprecedented resolution and sensitivity, ALMA showed us the detailed structure of the clouds,” said Ando, the lead author of the research paper...

Scientists detect comets outside our solar system

An artist’s conception of a view from within the Exocomet system KIC 3542116. Credit: Danielle Futselaar Team of professional and citizen scientists identifies tails of comets streaking past a distant star Jennifer Chu | MIT News Office Scientists from MIT and other institutions, working closely with amateur astronomers, have spotted the dusty tails of six exocomets — comets outside our solar system — orbiting a faint star 800 light years from Earth. These cosmic balls of ice and dust, which were about the size of Halley’s Comet and traveled about 100,000 miles per hour before they ultimately vaporized, are some of the smallest objects yet found outside our own solar system. The discovery marks the first time that an object as small as a comet has been detected using transit photometry, a technique by which astronomers observe a star’s light for telltale dips in intensity. Such dips signal potential transits, or crossings of planets or other objects in front of a star, ...

Hubble Observes Exoplanet that Snows Sunscreen

This is an artist’s impression of the exoplanet Kepler-13Ab as compared in size to several of the planets in the Solar System. The behemoth exoplanet is six times more massive than Jupiter. Kepler-13Ab is also one of the hottest known planets, with a dayside temperature of about 2700 °C. It orbits very close to the star Kepler-13A, which lies at a distance of 1730 light-years from Earth. Credit: NASA, ESA, and A. Feild (STScI) Nighttime Titanium Oxide Snow Leaves Dayside Cloud-Free and Cooler Travelers to the nightside of exoplanet Kepler-13Ab should pack an umbrella because they will be pelted with precipitation. But it's not the kind of watery precipitation that falls on Earth. On this alien world, the precipitation is in the form of sunscreen. Ironically, the sunscreen (titanium oxide) is not needed on this side of the planet because it never receives any sunlight. But bottling up some sunlight protection is a good idea if travelers plan on visiting the sizzling hot,...

SpaceTime

Search This Blog