Related Experiment Video
Updated: May 6, 2026
11:20
Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses
Published on: July 2, 2012
16.9K
Black-hole universe: time evolution
Chul-Moon Yoo1, Hirotada Okawa, Ken-ichi Nakao
1Gravity and Particle Cosmology Group, Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan and Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan.
Physical Review Letters
|November 5, 2013
Summary
This study simulates a black hole lattice toy model universe, finding its expansion mirrors the Einstein-de Sitter model. Large-scale cosmic expansion remains consistent despite local, nonlinear black hole structures.
Area of Science:
- Cosmology
- General Relativity
- Numerical Simulations
Background:
- Understanding the universe's large-scale expansion is crucial.
- Investigating the impact of local inhomogeneities on cosmic expansion is an ongoing challenge.
Purpose of the Study:
- To simulate the time evolution of a black hole lattice toy model universe.
- To compare the expansion law of this model with the Einstein-de Sitter universe.
Main Methods:
- Numerical solution of vacuum Einstein equations in a cubic box with a central black hole.
- Application of periodic boundary conditions.
- Definition of effective scale factors using surface area and edge length.
Main Results:
- The effective scale factors of the toy model closely approximate those of the Einstein-de Sitter universe.
- Local inhomogeneities, even highly nonlinear ones, do not significantly alter the global expansion law when the box size exceeds the black hole's horizon radius.
Conclusions:
- A black hole lattice toy model can effectively mimic the expansion of the Einstein-de Sitter universe.
- Cosmic expansion is robust against local nonlinear structures at large scales.
Related Concept Videos
01:21Schwarzschild Radius and Event Horizon
2.2K
No object with a finite mass can travel faster than the speed of light in a vacuum. This fact has an interesting consequence in the domain of extremely high gravitational fields.
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape...
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape...
2.2K
01:10Detection of Black Holes
1.7K
Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
1.7K
01:17Space-Time Curvature and the General Theory of Relativity
4.4K
In 1905, Albert Einstein published his special theory of relativity. According to this theory, no matter in the universe can attain a speed greater than the speed of light in a vacuum, which thus serves as the speed limit of the universe.
This has been verified in many experiments. However, space and time are no longer absolute. Two observers moving relative to one another do not agree on the length of objects or the passage of time. The mechanics of objects based on Newton's laws of...
This has been verified in many experiments. However, space and time are no longer absolute. Two observers moving relative to one another do not agree on the length of objects or the passage of time. The mechanics of objects based on Newton's laws of...
4.4K
01:22Generation Time
2.1K
Bacterial generation time, the period required for a bacterial population to double during its exponential growth phase, serves as a critical measure of microbial growth dynamics under optimal conditions. This parameter varies significantly across bacterial species and can be influenced by factors such as temperature, pH, and the availability of nutrients. For example, Escherichia coli can achieve a generation time of approximately 20 minutes, while Mycobacterium tuberculosis exhibits a much...
2.1K
01:18Conservation of Angular Momentum: Application
8.8K
A system's total angular momentum remains constant if the net external torque acting on the system is zero. Examples of such systems include a freely spinning bicycle tire that slows over time due to torque arising from friction, or the slowing of Earth's rotation over millions of years due to frictional forces exerted on tidal deformations. However in the absence of a net external torque, the angular momentum remains conserved. The conservation of angular momentum principle requires a...
8.8K
01:24Limits at Infinity
429
The function that decreases as the input becomes very large provides a clear example of how mathematical functions can behave at extreme values. When the input increases continuously, the output becomes smaller and smaller, getting closer to a particular fixed value. Although the output never actually reaches this value, it moves nearer to it without limit. This behavior is a fundamental concept in understanding how functions behave as the input grows indefinitely. The graphical representation...
429