Cosmological puzzles are tempting astronomers to rethink our simple picture of the universe – and ask whether dark matter is even stranger than we thought.
By Stuart Clark
Dark energy is one of the biggest mysteries in all the Universe. Is there any way to avoid ‘having to live with it?’
Explorations in dark matter are advancing with new experimental techniques designed to detect axions, leveraging advanced technology and interdisciplinary collaboration to uncover the secrets of this elusive component of the cosmos.
A ghost is haunting our universe. This has been known in astronomy and cosmology for decades. Observations suggest that about 85% of all the matter in the universe is mysterious and invisible. These two qualities are reflected in its name: dark matter.
Several experiments have aimed to unveil what it’s made of, but despite decades of searching, scientists have come up short. Now our new experiment, under construction at Yale University in the US, is offering a new tactic.
Researchers utilizing the European Gaia spacecraft have discovered a black hole in a binary system, located 1,500 light-years away and weighing 33 times the mass of the sun, making it the heaviest known in the Milky Way.
The black hole, discovered using data from the European Gaia spacecraft, is more than three times heavier than the known black holes in our galaxy.
Continue reading “Einstein’s Legacy Proven Again With Monumental Black Hole Discovery” »
It turns out that such cannibalism cannot explain the missing pulsar problem, according to Caizzo. “We found that in our current model PBHs are not able to disrupt these objects but this is only considering our simplified model of 2 body interactions,” he said. It doesn’t rule out the existence of PHBs, only that in specific instances, such capture isn’t happening.
So, what’s left to examine? If there are PHBs in the cores and they’re merging, no one’s seen them yet. But, the center of the Galaxy is a busy place. A lot of bodies crowd the central parsecs. You have to calculate the effects of all those objects interacting in such a small space. That “many-body dynamics” problem has to account for other interactions, as well as the dynamics and capture of PBHs.
Astronomers looking to use PBH-neutron star mergers to explain the lack of pulsar observations in the core of the Galaxy will need to better understand both the proposed observations and the larger populations of pulsars. The team suggests that future observations of old neutron stars close to Sgr A could be very useful. They’d help set stronger limits on the number of PBHs in the core. In addition, it would be useful to get an idea of the masses of these PBHs, since those on the lower end (asteroid-mass types) could interact very differently.
Most models for the overall shape and geometry of the Universe—including some exotic ones—are compatible with the latest cosmic observations.
Is the Universe simply connected like a sphere or does it contain holes like a doughnut or a more complicated structure? The topology of the Universe—that is, its overall geometry—remains far from settled, according to a collaboration of cosmologists. Despite past claims that observations of the cosmic microwave background (CMB) rule out various topologies, the researchers contend that many of these shapes, including some strange ones, have not been contradicted by the evidence [1].
The overall geometry of the Universe is thought to have been determined by quantum processes that unfolded in the initial moment of the big bang. Identifying the topology of the Universe would provide researchers with an important clue as to the nature of those quantum processes and could help them sift through the many proposed theories of the early Universe.
In the 20th century, many options abounded as to our cosmic origins. Today, only the Big Bang survives, thanks to this critical evidence.
Researchers from the University of Portsmouth’s Institute of Cosmology and Gravitation (ICG) have helped to detect a remarkable gravitational-wave signal, which could hold the key to solving a cosmic mystery.
The discovery is from the latest set of results announced by the LIGO-Virgo-KAGRA collaboration, which comprises more than 1,600 scientists from around the world, including members of the ICG, that seeks to detect gravitational waves and use them for exploration of fundamentals of science.
In May 2023, shortly after the start of the fourth LIGO-Virgo-KAGRA observing run, the LIGO Livingston detector in Louisiana, U.S., observed a gravitational-wave signal from the collision of what is most likely a neutron star with a compact object that is 2.5 to 4.5 times the mass of our sun.
