Special Issue "Advances in Loop Quantum Cosmology"

A special issue of Galaxies (ISSN 2075-4434).

Deadline for manuscript submissions: 1 April 2019

Special Issue Editor

Guest Editor
Prof. Kostas Kleidis

Department of Mechanical Engineering, Technological Education Institute of Central Macedonia, 62124 Serres, Greece
Website | E-Mail
Interests: general relativity; theoretical cosmology; quantum gravity

Special Issue Information

Dear Colleagues,

You are cordially invited to submit papers to the Special Issue of “Advances in Loop Quantum Cosmology”, which focuses on comprehending the pre-inflationary cosmological era, which is believed to be governed by quantum gravity (QG).

Loop quantum gravity (LQG) is a background independent, non-perturbative approach aimed at unifying general relativity (GR) and quantum physics. Loop quantum cosmology (LQC) is the application of LQG to cosmological settings. This new paradigm has provided some remarkable insights on QG, and has allowed for a systematic exploration of the very early Universe.

The scope of this Special Issue is to highlight recent developments on conceptual issues of LQC as well as the resulting phenomenological implications.

Cosmological spacetimes can provide the most appropriate setting to render significant progress on many conceptual and technical problems of QG. In cosmological models, Einstein’s equations hold to an excellent degree of approximation at low curvature, but they undergo major modifications in the Planck regime. In LQC, the current paradigm of cosmology changes and, hence, several unresolved questions can be addressed, as, for example, the avoidance of classical singularities; the way that a smooth, continuous spacetime can emerge from an underlying quantum theory; the way that the QG effects modify the classical field equations; the nature of time; quantum probabilities in the presence of external fields; and so on. Recently, the scalar–tensor reconstruction techniques were also extended to the context of LQC, and the holonomy corrections were taken into account. One of the striking results was that, when the holonomy corrections are considered, there are no Big Rip singularities at all.

Today, LQC can successfully face many of the long-standing problems of QG. New effects, originating from Planck-scale physics, can resolve the initial singularity of GR, while ensuring an agreement with Einstein’s theory at a low curvature. Clearly, the LQC framework has already been advanced sufficiently in order to meet phenomenology and observations.

Prof. Kostas Kleidis
Guest Editor

  1. Ashtekar, A.; Pawlowski, T.; Singh, P. Quantum nature of the Big Bang. Phys. Rev. Lett. 2006, 96, 141301, arXiv: gr-qc/0602086.
  2. Ashtekar, A.; Pawlowski, T.; Singh, P. Quantum nature of the Big Bang: An analytical and numerical investigation. Phys. Rev. D 2006, 73, 124038, arXiv: gr-qc/0604013.
  3. Ashtekar, A.; Pawlowski, T.; Singh, P. Quantum nature of the Big Bang: Improved dynamics. Rev. D 2006, 74, 084003, arXiv: gr-qc/0607039
  4. Ashtekar, A. An introduction to loop quantum gravity through Cosmology. Nuovo Cimento B 2007, 122, 135, arXiv: gr-qc/0702030.
  5. Mielczarek, J.; Szydlowski, M. Relic gravitons as the observable for loop quantum Cosmology. Phys. Lett. B 2007, 657, 20, doi:10.1016/j.physletb.2007.10.011, arXiv: 0705. 4449 [gr-qc].
  6. Ashtekar, A.; Corichi, A.; Singh, P. Robustness of key features of loop quantum Cosmology. Phys. Rev. D 2008, 77, 024046, arXiv: 0710.3565 [gr-qc].
  7. Bojowald, M. Consistent loop quantum Cosmology. Quantum Grav. 2009, 29, 075020, arXiv: 0811.4129 [gr-qc].
  8. Mielczarek, J.; Hrycyna, O.; Szydlowski, M. Effective dynamics of the closed loop quantum Cosmology. Cosmol. Astropart. Phys. 2009, 0911, 014, doi:10.1088/1475-7516/2009/11/ 014, arXiv: 0906.2503 [gr-qc].
  9. Ashtekar, A.; Singh, P. Loop Quantum Cosmology: A status report. Class. Quantum Grav. 2011, 28, 213001, arXiv: 1108.0893 [gr-qc].
  10. Haro, J.; Makarenko, A.N.; Myagky, A.N.; Odintsov, S.D.; Oikonomou, V.K. Bouncing loop quantum Cosmology in Gauss–Bonnet gravity. Rev. D 2015, 92, 124026, doi:10.1103/Phys. Rev. D 92 124026, arXiv: 1506.08273 [gr-qc].
  11. Oikonomou, K. Reconstructing the evolution of the Universe from loop quantum Cosmology scalar fields. Phys. Rev. D 2016, 94, 044004, doi:10.1103/Phys. Rev. D.94.044004, arXiv: 1607.07107 [gr-qc].
  12. Salo, L.A.; Amoros, J.; de Haro, J. Qualitative study in loop quantum Cosmology. Class. Quantum Grav. 2017, 34, 235001, doi:10.1088/1361-6382/aa9311, arXiv: 1612.05480 [gr-qc].
  13. Agullo, I.; Singh, P. Loop Quantum Cosmology: A Brief Review. In 100 Years of General Relativity; Ashtekar, A., Pullin, J. (eds.); World Scientific: Singapore, 2017, doi:10.1142/97898132200030007
  14. Kleidis, K.; Oikonomou, V.K. Loop quantum Cosmology scalar field models. Int. J. Geom. Methods Mod. Phys. 2018, 15, 1850071, doi:10.1142/S0219887818500718.

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Galaxies is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 350 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.


  • loop quantum gravity
  • loop quantum cosmology
  • quantum geometry
  • planck epoch
  • pre-inflationary era
  • initial singularity
  • hamiltonian formulation

Published Papers

This special issue is now open for submission.
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