Context: Researchers from Inter University Centre for Astronomy and Astrophysics (IUCAA) have studied primordial black holes(PBH) that were born as a result of a tiny increase in the potential energy levels of the universe.
More about the research:
- The study titled as ‘Primordial Black Holes from a tiny bump / dip in Inflation potential’ was published recently in the Journal of Cosmology and Astroparticle Physics.
- The study has confirmed that marginal rise in potential energy has resulted in the birth of several PBHs and also emitted very powerful gravitational waves.
About Primordial Black Holes (PBH)
- Origin:They were formed during the Hot Big Bang phase of the origin of the universe.
- Significance: Because of their association with Big Bang they are considered by many researchers among the principal candidates in explaining the nature of dark matter.
- Differences with other black holes: It is believed that they are formed as a result of collapsing radiations as opposed to the collapse of massive stars, which is the case of any other black holes.
- Extent of PBH: PBH can be massively large as 3000kms or be extremely tiny like the nucleus of an atom.
Origin of Primordial Black Holes (PBH) explained by new research:
- Big Bang and Cosmic inflation Phase:
- Very young universe was found to be active and expanding at a highly accelerated rate just after the big bang, nearly 14 billion years ago.
- This exponential growth in its size, experts say, was fuelled by the presence of a uniform energy field and density as the universe passed through the Cosmic Inflation phase.
- Association of marginal increase in the potential energy and Primordial Black Holes
- According to the scientists, as time passes, this uniform energy prevailing in the Inflation Field wanes out. As a result of this the universe resumes its normal decelerating rate.
- But before the energy dies out completely scientists have noticed that there could be a marginal increase in the potential energy for a very short time in the form of a bump, on to an otherwise dwindling energy-level graph.
- The potential energy of inflation could be higher just by 1 per cent, but could be significant enough to create vast differences in the densities.
- Role of the repulsive gravity in rapid expansion of universe:
- Gravity is normally attractive in nature.
- But according to scientists, what allowed the primitive universe to undergo rapid expansion was the Inflation field which contrarily possessed repulsive gravity.
- This pushed the universe to expand at a much faster rate than normal.
- Birth of galaxies,stars and PBH:
- Thereafter, the remnant energy possessed by this gravitational force got converted mainly into photons (light) in addition to protons, electrons, neutrons and other particles.
- As the universe continued to grow exponentially during the Cosmic Inflation phase, it sent across tiny quantum jitters.
- These fluctuations, released in a specific fashion, when sufficiently large, slowly give birth to galaxies and stars.
- Among those quantum fluctuations that were significantly large, helped form PBHs.
- Quantum is a discrete quantity of energy proportional in magnitude to the frequency of the radiation it represents.
- Creation of strong gravitational waves:
- The resultant bump in energy while producing PBHs also triggers very strong gravitational waves.
- Further studies of gravitational waves emerging from PBHs could give deeper insights as to how the energy was decaying.
About Big Bang theory
- The Big Bang Theory is the leading explanation about how the universe began.
- It is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now (and it could still be stretching).
- The Big Bang hypothesis states that all of the current and past matter in the Universe came into existence at the same time, roughly 13.8 billion years ago.
- At this time, all matter was compacted into a very small ball with infinite density and intense heat called a Singularity.
- Suddenly, the Singularity began expanding, and the universe as we know it began.
Big Bang timeline
About Black holes
- A black hole is a place in space where gravity pulls so much that even light can not get out.
- The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.
- Because no light can get out, people can't see black holes. They are invisible.
- Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently than other stars.