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Search results for “General Relativity”

1,000+ results for "General Relativity"

Beyond Einstein

Physicists at LSU and Penn State develop new mathematical equations that go beyond Einstein's theory of general relativity, showing that black hole singularities do not exist. The theory predicts a funnel to another branch of space-time instead.

SourceLouisiana State University·JournalPhysical Review Letters·DateDec 20, 2018

Beyond the black hole singularity

Loop quantum gravity allows physicists to extend gravitational physics beyond general relativity's limitations, enabling the analysis of black hole interiors. The theory predicts a repulsive force that can overwhelm classical gravity, potentially resolving the information paradox at black holes.

Searching for errors in the quantum world

A thought experiment by Renato Renner and Daniela Frauchiger reveals a paradoxical situation where indirect observation of a quantum mechanical object yields the opposite result of direct observation. The calculation shows that precisely this is not the case, creating a conundrum. While colleagues have proposed various solutions, none ...

SourceETH Zurich·JournalNature Communications·DateSep 18, 2018

Centenary of cosmological constant lambda

The cosmological constant was first introduced by Einstein in 1917 to make the static universe model work. However, after the discovery of cosmic expansion, it became marginalized until recent observations and experiments revived its relevance as a key component of dark energy theory.

SourceSpringer·JournalThe European Physical Journal H·DateJul 11, 2018

Einstein proved right in another galaxy

An international team confirms Albert Einstein's general theory of relativity by making the most precise test of gravity outside our solar system. By combining data from NASA's Hubble Space Telescope and the European Southern Observatory's Very Large Telescope, the researchers found that gravity behaves as predicted by GR on galactic s...

SourceUniversity of Portsmouth·JournalScience·DateJun 21, 2018

Can we tell black holes apart?

Astronomers used computer simulations to create images of accreting supermassive black holes in different gravity theories. They found that even highly non-Einsteinian black holes could mimic the appearance of standard black holes, highlighting the need for new techniques to distinguish them.

SourceGoethe University Frankfurt·JournalNature Astronomy·DateApr 17, 2018

The background hum of space could reveal hidden black holes

Researchers have developed a way to detect gravitational waves from faint black hole mergers, allowing them to study populations of black holes at vast distances. The new method is estimated to be one thousand times more sensitive than previous techniques, and will enable the detection of thousands of previously hidden black holes.

SourceMonash University·JournalPhysical Review X·DateApr 12, 2018

A new kind of star

Researchers have developed a novel mathematical model combining general relativity with quantum vacuum polarization, enabling the existence of ultracompact stars and new stellar configurations. The study suggests that these stars could be detectable in future gravitational wave observatories.

SourceScuola Internazionale Superiore di Studi Avanzati·JournalPhysical Review Letters·DateMar 8, 2018

Physicists lay groundwork to better understand the birth of the universe

Physicists Sebastian Deffner and Anthony Bartolotta developed techniques for describing the thermodynamics of very small systems with high energy, which could lead to a better understanding of the birth of the universe. They found that in their model system, the system was more likely to return multiple particles upon sending in just one.

SourceUniversity of Maryland Baltimore County·JournalPhysical Review X·DateMar 6, 2018

Black hole breakthrough: New insight into mysterious jets

Researchers gained new understanding of relativistic jets' behavior through advanced supercomputer simulations, revealing how space-time is dragged into the rotation of rotating black holes. The study confirms that tilted disks lead to precessing jets that periodically change their direction in the sky.

SourceNorthwestern University·JournalMonthly Notices of the Royal Astronomical Society·DateJan 10, 2018

A look into the fourth dimension

Researchers from ETH Zurich, USA, Germany, Italy, and Israel create a four-dimensional physical phenomenon in two dimensions using the quantum Hall effect. The team, led by Oded Zilberberg, demonstrates a virtual fourth dimension through topological pumping, enabling the observation of four-dimensional quantum Hall effect characteristics.

SourceETH Zurich·JournalNature·DateJan 4, 2018

Black hole pair born inside a dying star?

Researchers at Kyoto University have proposed a new theory on the formation of binary black holes within collapsing stars. Their study suggests that these black holes could form through dynamical fragmentation of the star's inner core, leading to two fragments becoming black holes and orbiting each other.

SourceKyoto University·JournalPhysical Review Letters·DateDec 18, 2017

Doing without dark energy

Three mathematicians argue that Einstein's General Relativity theory predicts cosmic acceleration due to an instability, contradicting the need for dark energy. The unstable Friedmann space-time exhibits accelerating local space-times with similar cosmic accelerations as dark energy theories.

Hot bodies are attractive

Researchers at UC Berkeley found that blackbody radiation from a warm object can attract cesium atoms, with an effect 20 times stronger than gravity. This discovery has implications for precise measurements of fundamental constants and tests of general relativity.

SourceUniversity of California - Berkeley·JournalNature Physics·DateDec 8, 2017

Physicist assumes the possibility of vestiges of an Universe previous to the Big Bang

Brazilian researcher Juliano Cesar Silva Neves challenges the standard cosmological model by proposing the elimination of the spacetime singularity and the possibility of a prior contraction phase. The current expansion may be preceded by contraction, with potential vestiges still present in the universe.

SourceFundação de Amparo à Pesquisa do Estado de São Paulo·JournalGeneral Relativity and Gravitation·DateNov 27, 2017

Patients report worse care experience in GP practices owned by limited companies

Research published in the Journal of the Royal Society of Medicine found that patients registered to general practices owned by limited companies reported worse experience of their care compared to those registered with independently owned practices. The study analyzed data from over 7,900 general practices in England and found signifi...

SourceSAGE·JournalJournal of the Royal Society of Medicine·DateNov 2, 2017