Hypothetical particles are proposed physical entities that extend or modify established particle content in a given theoretical framework, typically introduced to resolve inconsistencies, explain unexplained phenomena, or complete symmetries in high-energy and gravitational physics. As physical systems, they are characterized by well-defined quantum numbers, interaction types, mass scales, and roles in Lagrangian formulations, yet they lack direct experimental confirmation. Examples in model-building include particles postulated in supersymmetry, grand unified theories, dark matter and dark energy models, and quantum gravity scenarios, where their properties are constrained by consistency with known symmetries, renormalizability, cosmological evolution, and precision tests of the Standard Model and general relativity.
Axions are hypothetical light particles that could solve two different physics problems, as they could explain why some nuclear interactions don't violate time symmetry and are also promising dark matter candidates. Dark ...
Scientists search for "decaying" dark matter (DDM) because it offers unique signatures like specific X-ray or gamma-ray lines or neutrino signals not seen in normal matter, potentially revealing dark matter's particle nature, ...
Astronomy
Dec 17, 2025
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Neutron stars are ultra-dense star remnants made up primarily of nucleons (i.e., protons and neutrons). Over the course of millions of years, these stars progressively cool down, radiating heat into space.
A new theory for the origins of dark matter suggests that fast-moving, neutrino-like dark particles could have decoupled from Standard Model particles far earlier than previous theories had suggested.
Chemical rockets have taken us to the moon and back, but traveling to the stars demands something more powerful. Space X's Starship can lift extraordinary masses to orbit and send payloads throughout the solar system using ...
General Physics
Dec 1, 2025
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Determining the nature of dark matter, the invisible substance that makes up most of the mass in our universe, is one of the greatest puzzles in physics. New results from the world's most sensitive dark matter detector, LUX-ZEPLIN ...
General Physics
Sep 29, 2025
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Dark matter remains one of the biggest mysteries in fundamental physics. Many theoretical proposals (axions, WIMPs) and 40 years of extensive experimental searches have failed to provide any explanation of the nature of dark ...
General Physics
Sep 22, 2025
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About 80% of the universe's mass is thought to consist of dark matter. Yet, little is known about the composition and structure of the particles that make up dark matter, presenting physicists with some fundamental questions. ...
Astronomy
Sep 9, 2025
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Physicists from the University of Copenhagen have begun using the gigantic magnetic fields of galaxy clusters to observe distant black holes in their search for an elusive particle that has stumped scientists for decades.
Astronomy
Aug 15, 2025
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Quantum computers have the potential to solve problems far beyond the reach of today's fastest supercomputers. But today's machines are notoriously fragile. The quantum bits, or "qubits," that store and process information ...
Quantum Physics
Aug 5, 2025
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