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Archive for the ‘cosmology’ category: Page 260

Jan 9, 2021

Using the SYK model to examine the fast-charging process of quantum batteries

Posted by in categories: cosmology, quantum physics

The Sachdev-Ye-Kitaev (SYK) model, an exactly solvable model devised by Subir Sachdev and Jinwu Ye, has recently proved useful for understanding the characteristics of different types of matter. As it describes quantum matter without quasiparticles and is simultaneously a holographic version of a quantum black hole, it has so far been adopted by both condensed matter and high-energy physicists.

Researchers at University of Pisa and the Italian Institute of Technology (IIT) have recently used the SYK model to examine the charging protocols of quantum batteries. Their paper, published in Physical Review Letters, offers evidence of the potential of quantum mechanical resources for boosting the charging process of batteries.

“Previous theoretical studies laid down the idea that entanglement can be used to greatly speed up the charging process of a quantum battery,” Davide Rossini and Gian Marcello Andolina, two of the researchers who carried out the study, told Phys.org, via email. “However, a concrete solid-state model displaying such fast charging was missing, until now.”

Jan 8, 2021

New type of atomic clock keeps time even more precisely

Posted by in categories: cosmology, particle physics

A newly-designed atomic clock uses entangled atoms to keep time even more precisely than its state-of-the-art counterparts. The design could help scientists detect dark matter and study gravity’s effect on time.

Jan 8, 2021

Primordial black holes and the search for dark matter from the multiverse

Posted by in categories: cosmology, particle physics

Such primordial black holes (PBHs) could account for all or part of dark matter, be responsible for some of the observed gravitational waves signals, and seed supermassive black holes found in the center of our Galaxy and other galaxies. They could also play a role in the synthesis of heavy elements when they collide with neutron stars and destroy them, releasing neutron-rich material. In particular, there is an exciting possibility that the mysterious dark matter, which accounts for most of the matter in the universe, is composed of primordial black holes. The 2020 Nobel Prize in physics was awarded to a theorist, Roger Penrose, and two astronomers, Reinhard Genzel and Andrea Ghez, for their discoveries that confirmed the existence of black holes. Since black holes are known to exist in nature, they make a very appealing candidate for dark matter.

The recent progress in fundamental theory, astrophysics, and astronomical observations in search of PBHs has been made by an international team of particle physicists, cosmologists and astronomers, including Kavli IPMU members Alexander Kusenko, Misao Sasaki, Sunao Sugiyama, Masahiro Takada and Volodymyr Takhistov.

To learn more about primordial black holes, the research team looked at the early universe for clues. The early universe was so dense that any positive density fluctuation of more than 50 percent would create a black hole. However, cosmological perturbations that seeded galaxies are known to be much smaller. Nevertheless, a number of processes in the early universe could have created the right conditions for the black holes to form.

Jan 7, 2021

After decades of effort, scientists are finally seeing black holes—or are they?

Posted by in category: cosmology

Scientists hope to answer three specific questions: Do the observed black holes really have event horizons? Are they as featureless as the no-hair theorem says? And do they distort spacetime exactly as the Kerr metric predicts?


How do you prove that you’re observing a bizarre, featureless hole in the fabric of space and time?

Jan 4, 2021

Astronomers agree: Universe is nearly 14 billion years old

Posted by in categories: cosmology, physics

From an observatory high above Chile’s Atacama Desert, astronomers have taken a new look at the oldest light in the universe.

Their observations, plus a bit of cosmic geometry, suggest that the universe is 13.77 billion years old – give or take 40 million years. A Cornell researcher co-authored one of two papers about the findings, which add a fresh twist to an ongoing debate in the astrophysics community.

The new estimate, using data gathered at the National Science Foundation’s Atacama Cosmology Telescope (ACT), matches the one provided by the standard model of the universe, as well as measurements of the same light made by the European Space Agency’s Planck satellite, which measured remnants of the Big Bang from 2009 to ’13.

Jan 3, 2021

Astronomers Improve Their Distance Scale for the Universe. Unfortunately, it Doesn’t Resolve the Crisis in Cosmology

Posted by in category: cosmology

Astronomers have made the cosmic distant ladder more accurate, but that has only made the mystery of cosmic expansion even worse.


Measuring the expansion of the universe is hard. For one thing, because the universe is expanding, the scale of your distance measurements affects the scale of the expansion. And since light from distant galaxies takes time to reach us, you can’t measure what the universe is, but rather what it was. Then there is the challenge of the cosmic distance ladder.

The distance ladder stems from the fact that while we have lots of ways to measure cosmic distance, none of them work at all scales. For example, the greatest distances are determined by measuring the apparent brightness of supernovae in distant galaxies. That works great across billions of light-years, but there aren’t enough supernovae in the Milky Way to nearby measure distances. Perhaps the most accurate distance measurement uses parallax, which measures the apparent shift in the position of a star as the Earth orbits the Sun. Parallax is a matter of simple geometry, but it’s only accurate to a couple of thousand light-years.

Continue reading “Astronomers Improve Their Distance Scale for the Universe. Unfortunately, it Doesn’t Resolve the Crisis in Cosmology” »

Dec 30, 2020

China clamps down in hidden hunt for coronavirus origins

Posted by in categories: biotech/medical, cosmology, government

AP Exclusive: The Chinese government is tightly controlling all COVID-19 research under orders from President Xi Jinping, internal documents obtained by The AP show. As a result, China’s search for the origins of the virus has been cloaked in secrecy. In a sign of how sensitive research has become, police stopped scientists and confiscated their samples at a mineshaft where the closest known relative of the COVID-19 virus was found.


MOJIANG, China (AP) — Deep in the lush mountain valleys of southern China lies the entrance to a mine shaft that once harbored bats with the closest known relative of the COVID-19 virus.

The area is of intense scientific interest because it may hold clues to the origins of the coronavirus that has killed more than 1.7 million people worldwide. Yet for scientists and journalists, it has become a black hole of no information because of political sensitivity and secrecy.

Continue reading “China clamps down in hidden hunt for coronavirus origins” »

Dec 29, 2020

All Dark Matter in the Universe Could Be Primordial Black Holes – Formed From the Collapse of Baby Universes Soon After the Big Bang

Posted by in categories: cosmology, physics

The Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) is home to many interdisciplinary projects which benefit from the synergy of a wide range of expertise available at the institute. One such project is the study of black holes that could have formed in the early universe, before stars and galaxies were born.

Such primordial black holes (PBHs) could account for all or part of dark matter, be responsible for some of the observed gravitational waves signals, and seed supermassive black holes found in the center of our Galaxy and other galaxies. They could also play a role in the synthesis of heavy elements when they collide with neutron stars and destroy them, releasing neutron-rich material.

In particular, there is an exciting possibility that the mysterious dark matter, which accounts for most of the matter in the universe, is composed of primordial black holes. The 2020 Nobel Prize in physics was awarded to a theorist, Roger Penrose, and two astronomers, Reinhard Genzel and Andrea Ghez, for their discoveries that confirmed the existence of black holes. Since black holes are known to exist in nature, they make a very appealing candidate for dark matter.

Dec 28, 2020

Searching for invisible axion dark matter with a new multiple-cell cavity haloscope

Posted by in categories: cosmology, particle physics

Over the past few decades, many experimental physicists have been probing the existence of particles called axions, which would result from a specific mechanism that they think could explain the contradiction between theories and experiments describing a fundamental symmetry. This symmetry is associated with a matter-antimatter imbalance in the Universe, reflected in interactions between different particles.

If this mechanism took place in the early Universe, such a particle might have a very small mass and be ‘invisible. Subsequently, researchers proposed that the might also be a promising candidate for dark matter, an elusive, hypothetical type of matter that does not emit, reflect or absorb light.

While dark matter has not yet been experimentally observed, it is believed to make up 85% of universe’s mass. Detecting axions could have important implications for ongoing dark matter experiments, as it could enhance the present understanding of these elusive particles.

Dec 28, 2020

Is Dark Energy Really “Repulsive Gravity”?

Posted by in category: cosmology

Circa 2012 o.o


“Repulsive gravity”—a powerful repulsion between matter and antimatter—could explain the force known as dark energy, a new theory claims.