Researchers from the Institute of Space Science offer a unique way to search for microscopic black holes

Reprezentare artistică a două cascade de particule. Cercetătorii ISS spun că un astfel de eveniment format din două cascade distincte este semnatura unică a dezintegrarii unei găuri negre cuantice. Credit: ISS
The artistic representation of two particle falls. The ISS researchers say that such an event, composed of two distinct falls, is the unique signature of a quantum black hole’s disintegration. Credit: ISS

Three researchers from the Institute of Space Science (ISS) located on the Magurele Physics Platform propose a unique fingerprint to identify the disintegration of microscopic black holes – quantum black holes of very small dimensions, whose existence is still hypothetical. The identification of the signature they proposed based on observations can confirm the string theory and can change physics as we know it today. The contributions of the Romanian researchers have been published in the Journal of High Energy Physics, in Astroparticle Physics, and the third article is being published right now in an internationally renowned publication.

The current physics theories say that the minimum mass of a black hole is about 22 micrograms, known as the Planck mass. Only in string theory [1] models with extra dimensions, however, the Planck mass can be 1016 times smaller. In these conditions, due to the interaction between ultra-high energies cosmic rays [2] and Earth’s atmosphere nucleuses, it is possible to create the so-called microscopic black holes, whose existence is not yet proven.

The researchers from the Institute of Space Sciences (ISS), Dr. Octavian Micu, PhD. Laurentiu Caramete and PhD. Arsene Nicuşor propose in the published articles a unique way to confirm the existence of disintegration and quantum black holes. When ultra-high energies cosmic rays interact with nucleuses from the Earth’s atmosphere, they form then the microscopic black holes, which instantly disintegrates. The cascades of secondary particles resulting from the disintegration leaves, according to the ISS researchers, a unique touch. A similar process occurs in the case of neutrinos [3] at the interaction with water or ice nucleuses. For both scenarios, there are already international collaborations that study these interactions and could see the signature proposed by the Romanian researchers.

The Pierre Auger Observatory collaboration, in which ISS  became official partner in December 2012, is the largest experiment in the world designed to study cosmic rays, while the neutrino observatories,  IceCube located at the South Pole and the future KM3NeT which will be located in the Mediterranean Sea, are experiments for the study of neutrinos. If observations of these collaborations identify the experimental signatures proposed by the Romanian researchers, their contribution will confirm the existence of extra dimensions and the validity of string theory, and will revolutionize physics.

Dr. Octavian Micu and his research team consists of PhD. Laurentiu Caramete and PhD. Arsene Nicuşor, all of them part of the ISS Cosmology and Astroparticle Physics Department, led by Dr. Lucia Popa. Their research is funded by UEFISCDI project UEFISCDI, PN-II-RU-TE-2011-3-0184.

Simulare a semnăturii lăsate de dezintegrarea unei găuri negre cuantice. Credit: ISS
Simulare a semnăturii lăsate de dezintegrarea unei găuri negre cuantice. Credit: ISS

The Institute of Space Science (ISS), located in Magurele, Romania, develops research projects in various fields, like astroparticle physics, high energy physics, astrophysics and cosmology, space plasma physics and applied research, design and development of space technology activities. ISS has been involved in collaborations and partnerships nationally and internationally renowned (CERN-ALICE, ANTARES, KM3NeT, Pierre Auger Observatory), in ESA space program through missions such as Euclid, Planck, Cluster and has collaborated with NASA at the first Romanian experiment sent on the International Space Station.

Additional information

[1] The String theory is an unifying theory that tries to explain all the elementary particles and fundamental forces of the universe, shaping them as vibrations of microscopic strings.

[2] The ultra-high energies cosmic rays are high energies particles, several orders of magnitude higher than the energy of particles produced by the LHC particle accelerator in Geneva. Scientists believe that cosmic rays would come from active black holes or supernove. Their study is important because they are samples that we get from outside our solar system. Studying their chemical composition is a way to find out clues about our own origins, about how our solar system has evolved and about our galaxy dynamics.

[3] Neutrinos are subatomic elementary particles, electrically neutral, which interact via the weak force. Produced as a result og some radioactive decays or nuclear reactions such as those from the sun or from nuclear reactors, neutrinos can originating from distant sources: gamma-ray bursts, supernovae or the collision of stars.


  1. Journal of High Energy Physics 1211 (2012), pp. 104, “Quantum Black Holes from Cosmic Rays”, X. Calmet, L.I. Caramete, O. Micu.
  2. Astroparticle Physics, 54C (2014), pp. 132-138, “Back-to-back black holes decay signature at neutrino observatories”, N. Arsene, X. Calmet, L.I. Caramete, O. Micu.
  3. În curs de publicare, e-Print: arXiv:1310.2205 Quantum Black Holes Effects on the Shape of Extensive Air Showers”, N. Arsene, L.I. Caramete, P.B. Denton, O. Micu.

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