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.


Image Source:IE