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Category: cosmology – Page 276

WSU Master Class: Inflationary Cosmology with Alan Guth

Breakthrough Prize winner Alan Guth developed the theory of inflation to answer to our cosmic origins. It’s one of the most studied and debated theories in cosmology, with research propelling Guth’s work to the forefront of scientific conversation.

In this Master Class, Professor Guth addresses what experiments could potentially rule out the BICEP2 results. Since recording this in 2017, the Planck spacecraft collected the data that Professor Guth anticipated, which shows that the initial observations were likely an artifact of interstellar dust, not primordial gravitational waves.

This lecture was recorded on xyz at the World Science Festival in New York City.

Experience the associated free online course at World Science U:

Official Site: https://www.worldscienceu.com.

Laniakea, our local supercluster, is being destroyed

On the largest cosmic scales, planet Earth appears to be anything but special. Like hundreds of billions of other planets in our galaxy, we orbit our parent star; like hundreds of billions of solar systems, we revolve around the galaxy; like the majority of galaxies in the Universe, we’re bound together in either a group or cluster of galaxies. And, like most galactic groups and clusters, we’re a small part of a larger structure containing over 100,000 galaxies: a supercluster. Ours is named Laniakea: the Hawaiian word for “immense heaven.”

Superclusters have been found and charted throughout our observable Universe, where they’re more than 10 times as rich as the largest known clusters of galaxies. Unfortunately, owing to the presence of dark energy in the Universe, these superclusters ⁠— including our own ⁠— are only apparent structures. In reality, they’re mere phantasms, in the process of dissolving before our very eyes.

The Universe as we know it began some 13.8 billion years ago with the Big Bang. It was filled with matter, antimatter, radiation, etc.; all the particles and fields that we know of today, and possibly even more. From the earliest instants of the hot Big Bang, however, it wasn’t simply a uniform sea of these energetic quanta. Instead, there were tiny imperfections ⁠— at about the 0.003% level ⁠— on all scales, where some regions had slightly more or slightly less matter and energy than average.

Researchers detect 1st merger between black holes with eccentric orbits

Using hundreds of computer simulations, the researchers found that the gravitational wave signals from GW150521 are best explained by a high-eccentricity, according to the statement.

The study also sheds new light on how some of the black hole mergers detected by the Laser Interferometer Gravitational-wave Observatory (LIGO) and its European counterpart, Virgo, are so much heavier than previously thought possible. Their findings were published Jan. 20 in the journal Nature Astronomy.

Studying the big bang with artificial intelligence

It could hardly be more complicated: tiny particles whir around wildly with extremely high energy, countless interactions occur in the tangled mess of quantum particles, and this results in a state of matter known as “quark-gluon plasma”. Immediately after the Big Bang, the entire universe was in this state; today it is produced by high-energy atomic nucleus collisions, for example at CERN.

Such processes can only be studied using high-performance computers and highly complex computer simulations whose results are difficult to evaluate. Therefore, using artificial intelligence or machine learning for this purpose seems like an obvious idea. Ordinary machine-learning algorithms, however, are not suitable for this task. The mathematical properties of particle physics require a very special structure of neural networks. At TU Wien (Vienna), it has now been shown how neural networks can be successfully used for these challenging tasks in particle physics.

Extraordinary Black Hole — Unlike Any Other — Discovered in Neighboring Galaxy

The discovery, one of the only confirmed intermediate-mass black holes, lives in an equally rare object known as a low-mass, stripped nucleus.

Astronomers discovered a black hole unlike any other. At one hundred thousand solar masses, it is smaller than the black holes we have found at the centers of galaxies, but bigger than the black holes that are born when stars explode. This makes it one of the only confirmed intermediate-mass black holes, an object that has long been sought by astronomers.

“We have very good detections of the biggest, stellar-mass black holes up to 100 times the size of our sun, and supermassive black holes at the centers of galaxies that are millions of times the size of our sun, but there aren’t any measurements of black between these. That’s a large gap,” said senior author Anil Seth, associate professor of astronomy at the University of Utah and co-author of the study. “This discovery fills the gap.”

The End of Cosmic Dark Ages: How NASA’s Roman Space Telescope Could Expand on Hubble’s Deepest View

A team of astrophysicists has created a simulated image that shows how the Nancy Grace Roman Space Telescope could conduct a mega-exposure similar to but far larger than Hubble’s celebrated Ultra Deep Field Image. This Hubble observation transformed our view of the early universe, revealing galaxies that formed just a few hundred million years after the big bang.

“Roman has the unique ability to image very large areas of the sky, which allows us to see the environments around galaxies in the early universe,” said Nicole Drakos, a postdoctoral scholar at the University of California Santa Cruz, who led the study. “Our study helps demonstrate what a Roman ultra-deep field could tell us about the universe, while providing a tool for the scientific community to extract the most value from such a program.”