Smallest object in the universe
Pro Research Analysisby 
Searched over 200M research papers
The Smallest Objects in the Universe: A Comprehensive Overview
Smallest Particles in the Universe
Planck Scale Particles
Theoretical physics predicts the existence of the smallest possible particles, often referred to as Planck scale particles. These particles are hypothesized to have extremely small radii and are derived from fundamental physical constants using equations from Planck, Maxwell, and Einstein3. These particles represent the smallest conceivable units of matter and energy, potentially offering insights into the origins of the universe.
Smallest Astronomical Objects
Neutron Stars
Neutron stars are among the smallest and densest astronomical objects observable in the universe. Typically containing about 1.4 solar masses within a diameter of approximately 15 kilometers, neutron stars are incredibly dense and compact6. Despite their small size, they play a crucial role in astrophysics and are studied extensively using multiwavelength observations to understand their properties and behaviors better.
Microlensing Planets
Microlensing techniques have identified some of the smallest planets, such as OGLE-2019-BLG-0960 Lb, which has a mass ratio of 1.2–1.6 × 10⁻⁵ relative to its host star5. These planets are detected through their gravitational effects on light from distant stars, demonstrating the sensitivity of current observational methods to detect even the smallest planetary bodies.
Smallest Dark Matter Structures
Dark Matter Microhalos
In the context of cold dark matter (CDM) cosmology, microhalos are the smallest dark matter structures expected to form. These microhalos, which can be as small as Earth-mass or even smaller, are considered the densest dark matter objects in the universe4 7. High-resolution simulations indicate that these microhalos follow specific density profiles and are abundant throughout the dark matter distribution, making them significant for indirect dark matter detection efforts4 7.
Implications for Dark Matter Detection
The properties of dark matter microhalos are closely linked to the nature of dark matter and the physics of the early universe. Their high density and abundance suggest that they could significantly contribute to dark matter annihilation signals, which are crucial for astrophysical dark matter detection4 7. Understanding these microhalos can provide valuable insights into the fundamental characteristics of dark matter.
Conclusion
The smallest objects in the universe span a wide range of scales, from theoretical Planck scale particles to observable neutron stars and microlensing planets. Additionally, dark matter microhalos represent the smallest and densest dark matter structures, playing a crucial role in our understanding of the universe's composition and evolution. Each of these small-scale objects offers unique insights into the fundamental nature of matter, energy, and the cosmos.
Sources and full results
Most relevant research papers on this topic
Smallest universe of negative curvature.
The smallest known three-dimensional closed manifold of curvature k≡−1 was discovered a few years ago by Weeks. This kind of manifold is constructed from a hyperbolic polyhedron with faces pairwise identified. Here it is used as the comoving spatial section of a Friedmann cosmological model, in the spirit of Ellis and Schreiber's idea of small universes. Its nontrivial global topology has the effect of producing multiple images of single cosmic sources, and this is the basis of an attempt to solve a famous controversy about the redshifts of quasars
Calculation Of Radius And Energy Of Smallest Particle In The Universe
This theory predicts the existence of smallest particle Pe and calculates its radius and maximum energy using Planck, Maxwell, and Einstein's equations, potentially leading to new discoveries.
Density profiles of CDM microhalos and their implications for annihilation boost factors
CDM microhalos have steeper inner density profiles, contributing significantly to indirect dark matter detection signals, and their abundance in the present-day dark matter distribution.
Highly CitedOGLE-2019-BLG-0960 Lb: the Smallest Microlensing Planet
The smallest mass-ratio microlensing planet found to date, OGLE-2019-BLG-0960, demonstrates that current experiments are powerful enough to robustly measure the slope of the mass-ratio function below the break in the mass-ratio function.
Extremely large telescopes and the extremely small sources
Large telescopes with multiwavelength capabilities are crucial for understanding the properties and behavior of neutron stars, which are currently poorly understood.
Evolution of dark matter microhalos through stellar encounters
Our framework accurately predicts the evolution of dark matter microhalos' density profiles through stellar encounters, aiding in understanding their populations within galactic halos.
EDGE: the mass–metallicity relation as a critical test of galaxy formation physics
The stellar mass-metallicity relation of the smallest galaxies provides a unique constraint on galaxy formation physics, as it differentiates galaxy formation models based on feedback effects.
Inflationary Cosmology: Exploring the Universe from the Smallest to the Largest Scales
Inflationary cosmology offers a promising framework for understanding the universe's behavior, with predictions about its shape, large-scale smoothness, and smaller scale structure being tested with new astronomical measurements.
Highly Cited