DESI’s sky map suggests black holes create dark energy using the ash of dead stars.
A new set of data strengthens the case that dark energy’s influence on the universe—long believed to be constant—is actually changing over cosmic time.
Category: cosmology – Page 19
What came before the Big Bang? Supercomputers may hold the answer
Scientists are rethinking the universe’s deepest mysteries using numerical relativity, complex computer simulations of Einstein’s equations in extreme conditions. This method could help explore what happened before the Big Bang, test theories of cosmic inflation, investigate multiverse collisions, and even model cyclic universes that endlessly bounce through creation and destruction.
A new perspective on how cosmological correlations change based on kinematic parameters
To study the origin and evolution of the universe, physicists rely on theories that describe the statistical relationships between different events or fields in spacetime, broadly referred to as cosmological correlations. Kinematic parameters are essentially the data that specify a cosmological correlation—the positions of particles, or the wavenumbers of cosmological fluctuations.
Changes in cosmological correlations influenced by variations in kinematic parameters can be described using so-called differential equations. These are a type of mathematical equation that connect a function (i.e., a relationship between an input and an output) to its rate of change. In physics, these equations are used extensively as they are well-suited for capturing the universe’s highly dynamic nature.
Researchers at Princeton’s Institute for Advanced Study, the Leung Center for Cosmology and Particle Astrophysics in Taipei, Caltech’s Walter Burke Institute for Theoretical Physics, the University of Chicago, and the Scuola Normale Superiore in Pisa recently introduced a new perspective to approach equations describing how cosmological correlations are affected by smooth changes in kinematic parameters.
Self-consistent model incorporates gas self-gravity effects to address accretion across cosmic scales
A research team led by Prof. Jiao Chengliang at the Yunnan Observatories of the Chinese Academy of Sciences, along with collaborators, has introduced a self-consistent model that addresses long-unresolved theoretical gaps in the study of self-gravitating spherical accretion. The study was recently published in The Astrophysical Journal.
Accretion, the fundamental astrophysical process by which matter is drawn onto a central celestial object (such as a black hole or star), underpins our understanding of phenomena ranging from star formation to black hole growth. For decades, the classical Bondi model—developed in the 1950s and still widely used today—has served as the backbone of accretion research.
However, this foundational framework overlooks a critical factor: the self-gravity of the gas being accreted. This omission, the researchers note, can drastically alter flow structures and accretion rates in high-density astrophysical environments, limiting the model’s accuracy in key scenarios.
Two quantum computers with 20 qubits manage to simulate information scrambling
Four RIKEN researchers have used two small quantum computers to simulate quantum information scrambling, an important quantum-information process. This achievement illustrates a potential application of future quantum computers. The results are published in Physical Review Research.
Still in their infancy, quantum computers are only just beginning to be used for applications. But they promise to revolutionize computing when they become a mature technology.
One possible application for quantum computers is simulating the scrambling of quantum information—a key phenomenon that involves the spread of information in quantum systems ranging from strange metals to black holes.
New measurement station in Brazil: Quantum technology expands global network in search for dark matter
A highly sensitive quantum sensor from Jena has traveled nearly 9,000 kilometers: by truck to Hamburg, by ship across the Atlantic, and finally overland to Vassouras, Brazil.
At the campus of the Observatório Nacional, researchers from the Leibniz Institute of Photonic Technology (Leibniz-IPHT) in Jena, together with Brazilian partners, have installed a new measurement station. It is part of the worldwide GNOME project and is designed to help address one of the great unsolved questions in modern physics: the nature of dark matter.
Dark matter cannot be directly detected with conventional measurement methods. However, it demonstrably influences the motion of galaxies and the structure of the cosmos. Understanding its nature remains one of the central open problems in physics.
Exoplanets could be key to finding mysterious dark matter: Study
Dark matter could turn exoplanets into tiny black holes, shocking study reveals.
A study suggests that exoplanets could be used to search for dark matter — the elusive substance that makes up 85% of the universe’s matter.
Dark matter’s gravitational pull proves it exists, but we’ve never been able to directly find it.
Now, the University of California, Riverside, study proposes that exoplanets, especially large, gaseous ones like Jupiter, could act as natural laboratories for dark matter search.
X Particles Detected Inside LHC for the First Time Ever!
Physicists at the LHC have recently identified a collection of approximately one hundred “X particles” originating from the early moments of the Big Bang. These findings, which may lead to a deeper understanding of the universe, have been published in the Physical Review Letters journal.
Particle accelerators bring particles into high-speed collisions. The largest of these is the Large Hadron Collider (LHC), located near Geneva. The purpose of these experiments is to simulate aspects of the Big Bang and to examine how matter behaves under those conditions.
In recent years, these high-energy collisions have led to the discovery of several theorized particles. More recently, physicists have detected about a hundred short-lived “X particles,” so named due to their mysterious structures, amid billions of elementary particles.
What happened before the Big Bang? Computational method may provide answers
We’re often told it is “unscientific” or “meaningless” to ask what happened before the Big Bang. But a new paper by FQxI cosmologist Eugene Lim, of King’s College London, UK, and astrophysicists Katy Clough, of Queen Mary University of London, UK, and Josu Aurrekoetxea, at Oxford University, UK, published in Living Reviews in Relativity, proposes a way forward: using complex computer simulations to numerically (rather than exactly) solve Einstein’s equations for gravity in extreme situations.
