pulsars – Quanta Magazine

Some Physicists See Signs of Cosmic Strings From the Big Bang

Thomas Lewton — Tue, 29 Sep 2020 14:30:58 +0000

Cosmologists think that at the beginning of the universe, all the forces of nature were, for a brief fraction of a second, unified. But as the universe expanded and cooled, this superforce condensed into its familiar parts: gravity, electromagnetism and the strong and weak forces. According to some calculations, the cosmos might have cooled so quickly that the fabric of space-time became fractured...

Source

The Most-Magnetic Objects in the Universe Attract New Controversy

Erika K. Carlson — Mon, 28 Oct 2019 14:45:01 +0000

Magnetars have long been an astrophysical mystery. These compact hunks of nuclear matter — the ultradense remnants of supermassive stars — generate the most extreme magnetic fields in the universe. Researchers have debated exactly how these magnetic fields come about. But a new study of the explosions that gave rise to magnetars suggests that a long-favored theory might not hold up. The idea of a...

Source

Dark Matter Gets a Reprieve in New Analysis

Charlie Wood — Mon, 29 Apr 2019 14:19:27 +0000

The galactic center shines too brightly, like the glow of a metropolis at night where maps show only a town. To mend their cosmic cartography, astrophysicists have spent years debating what could be powering this excess of energetic light. In 2015 the arguments appeared to swing decisively in favor of a somewhat prosaic explanation — that a large population of dim neutron stars was responsible.

Source

Troubled Times for Alternatives to Einstein’s Theory of Gravity

Katia Moskvitch — Mon, 30 Apr 2018 14:00:38 +0000

Miguel Zumalacárregui knows what it feels like when theories die. In September 2017, he was at the Institute for Theoretical Physics in Saclay, near Paris, to speak at a meeting about dark energy and modified gravity. The official news had not yet broken about an epochal astronomical measurement — the detection, by gravitational wave detectors as well as many other telescopes...

Source

Astronomers Trace Radio Burst to Extreme Cosmic Neighborhood

Katia Moskvitch — Wed, 10 Jan 2018 18:00:36 +0000

On Christmas Eve 2016, Andrew Seymour, an astronomer at the Arecibo Observatory in Puerto Rico, kissed his 4-year-old daughter, Cora Lee, goodnight, telling her he was off to track Santa. He walked to the well-worn telescope, occasionally passing revelers riding horses through the empty streets — a common sight in Arecibo during the holidays. Sometimes a lonely firework would light up in the...

Source