Archive for the ‘cosmology’ category: Page 5

Jun 15, 2022

Scientists discover rapidly growing black hole

Posted by in category: cosmology

The fastest-growing black hole of the last 9 billion years has been discovered by an international team led by astronomers at The Australian National University (ANU).

The black hole consumes the equivalent of one Earth every second and shines 7,000 times brighter than all the light from our own galaxy, making it visible to well-equipped backyard .

Lead researcher Dr. Christopher Onken and his co-authors describe it as a “very large, unexpected needle in the haystack.”

Jun 14, 2022

Grand Unification as a Bridge Between String Theory And Phenomenology

Posted by in categories: cosmology, particle physics, quantum physics

Circa 2006 string theory would explain everything even extradimensional beings or even weird phenomenon. Basically it could even explain something even greater about our existence that even a God level entity had a grand design of our universe. It could even explain miracles by these entities using string theory. Even Einstein thought that there could be a great designer and oddly enough this could explain all things in physics and our world even an infinite multiverse that our universe is much more odd then we previously thought. String theory could even essentially be the next step after quantum mechanics.

In the first part of this paper, we explain what empirical evidence points to the need for having an effective grand unification-like symmetry possessing the symmetry SU-color in 4D. If one assumes the premises of a future predictive theory including gravity — be it string/M-theory or a reincarnation — this evidence then suggests that such a theory should lead to an effective grand unification-like symmetry as above in 4D, near the string-GUT-scale, rather than the standard model symmetry. Advantages of an effective supersymmetric G(224) = SU L × SU R × SU c or SO(10) symmetry in 4D in explaining (i) observed neutrino oscillations, (ii) baryogenesis via leptogenesis, and (iii) certain fermion mass-relations are noted. And certain distinguishing tests of a SUSY G(224) or SO(10)-framework involving CP and flavor violations (as in μ → eγ, τ → μγ, edm’s of the neutron and the electron) as well as proton decay are briefly mentioned.

Recalling some of the successes we have had in our understanding of nature so far, and the current difficulties of string/M-theory as regards the large multiplicity of string vacua, some comments are made on the traditional goal of understanding vis a vis the recently evolved view of landscape and anthropism.

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Jun 14, 2022

Scientists accidentally discover black hole so big you can spot it with a backyard telescope

Posted by in category: cosmology

Now, an international team of researchers say they have discovered a supermassive black hole that gobbles up the equivalent of one Earth every second.

By looking at other luminous objects that are billions of years old, the team confirmed the newly discovered behemoth was the brightest and fastest-growing supermassive black hole of the past 9 billion years (that we know of).

Located in the bright constellation of Centaurus, this luminous cosmic beast is more than 500 times larger than the supermassive black hole at the centre of our own galaxy.

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Jun 14, 2022

Hubble spies stellar ‘ghost’ wandering the Milky Way galaxy

Posted by in category: cosmology

For the first time, the Hubble Space Telescope has detected a lone object drifting through our Milky Way galaxy – the invisible, ghostly remains of a once radiant star.

When stars massive enough to dwarf our sun die, they explode in a supernova and the remaining core is crushed by its own gravity, forming a black hole.

Sometimes, the explosion may send the black hole into motion, hurtling across the galaxy like a pinball. By rights, there should be a lot of roving black holes known to scientists, but they are practically invisible in space and therefore very difficult to uncover.

Jun 14, 2022

A celestial loner might be the first known rogue black hole

Posted by in category: cosmology

The object could be the first isolated stellar-mass black hole identified in the Milky Way — or it might be an unusually heavy neutron star.

Jun 12, 2022

NASA’s retro video game lets you collect celestial objects like a cosmic connoisseur

Posted by in categories: cosmology, entertainment

Jun 12, 2022

Astronomers just saw a black hole flip its entire magnetic field for the first time!

Posted by in category: cosmology

Jun 12, 2022

Imaging Milky Way’s black hole: The exciting story began 100 years ago!

Posted by in category: cosmology

Jun 12, 2022

A collision that shook the universe! The first detection of a black hole gulping a neutron star

Posted by in category: cosmology

Jun 11, 2022

Contrasting the fuzzball and wormhole paradigms for black holes

Posted by in categories: cosmology, evolution, quantum physics

Circa 2021 Evidence of string theory by black holes as fuzzballs.

Abstract: We examine an interesting set of recent proposals describing a ‘wormhole paradigm’ for black holes. These proposals require that in some effective variables, semiclassical low-energy dynamics emerges at the horizon. We prove the ‘effective small corrections theorem’ to show that such an effective horizon behavior is not compatible with the requirement that the black hole radiate like a piece of coal as seen from outside. This theorem thus concretizes the fact that the proposals within the wormhole paradigm require some nonlocality linking the hole and its distant radiation. We try to illustrate various proposals for nonlocality by making simple bit models to encode the nonlocal effects. In each case, we find either nonunitarity of evolution in the black hole interior or a nonlocal Hamiltonian interaction between the hole and infinity; such an interaction is not present for burning coal. We examine recent arguments about the Page curve and observe that the quantity that is argued to follow the Page curve of a normal body is not the entanglement entropy but a different quantity. It has been suggested that this replacement of the quantity to be computed arises from the possibility of topology change in gravity which can generate replica wormholes. We examine the role of topology change in quantum gravity but do not find any source of connections between different replica copies in the path integral for the Rényi entropy. We also contrast the wormhole paradigm with the fuzzball paradigm, where the fuzzball does radiate like a piece of coal. Just as in the case of a piece of coal, the fuzzball does not have low-energy semiclassical dynamics at its surface at energies $E\sim T$ (effective dynamics at energies $E\gg T$ is possible under the conjecture of fuzzball complementarity, but these $E\gg T$ modes have no relevance to the Page curve or the information paradox).

From: Marcel Hughes [view email]

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