| Ref.No: | 61518700 |
| Start date: | 17.07.2024 |
| End date: | 16.06.2027 |
| Approval date: | 17.07.2024 |
| Department: | APPLIED MATHEMATICAL & PHYSICAL SCIENCES |
| Sector: | PHYSICS |
| Financier: | 5η ΠΡΟΚΗΡΥΞΗ ΕΛΙΔΕΚ Υ.Δ., ELIDEK |
| Budget: | 31.500,00 € |
| Public key: | Ψ03Π46ΨΖΣ4-ΤΤΚ |
| Scientific Responsible: | Assoc. Prof. KONSTANTINOS ANAGNOSTOPOULOS |
| Email: | konstant@mail.ntua.gr |
| Description: | WE CONSIDER A NOVEL APPROACH TO THE EVOLUTION OF THE UNIVERSE BASED ON SPACETIME GEOMETRIES WITH TORSION AND GRAVITATIONAL ANOMALIES, DESCRIBING THE UNIVERSE IN EARLY EPOCHS. WE ASSOCIATE THE TORSION DEGREES OF FREEDOM TO AXIONS WHICH CAN PLAY THE ROLE OF DARK MATTER. WE CONSIDER COSMOLOGIES INSPIRED FROM STRING THEORY, BASED ON THE BOSONIC MASSLESS GRAVITATIONAL MULTIPLET OF SUPERSTRINGS. WE DISCUSS CONDENSATION OF PRIMORDIAL GRAVITATIONAL WAVES WHICH LEAD TO METASTABLE DE-SITTER PHASES IN THE EARLY UNIVERSE, WHICH IS OF RUNNING VACUUM TYPE, NOT REQUIRING EXTERNAL INFLATONS. IN THE PRESENCE OF CHIRAL GRAVITATIONAL WAVES, THE CHERN-SIMONS GRAVITATIONAL ANOMALY, COUPLED TO THE TORSION-INDUCED AXION, IS NON-VANISHING. WE ALSO SHALL DISCUSS THE ORIGIN OF PRIMORDIAL GRAVITATIONAL WAVES. ANOTHER SOURCE FOR CHERN-SIMONS GRAVITATIONAL ANOMALIES ARE DISTRIBUTIONS OF PRIMORDIAL BLACK HOLES THAT CAN BE GENERATED FROM QUANTUM VACUUM. SUCH PRIMORDIAL BLACK HOLES CAN PLAY THE ROLE OF PART OF DARK MATTER, ESPECIALLY BECAUSE THEIR ENERGY DENSITIES CAN BE ENHANCED DURING INFLATION, IN A WAY THAT WE SHALL SPECIFY IN THIS THESIS. DURING THE EXIT FROM INFLATION, CHIRAL MATTER IS PRODUCED, LEADING TO THE CANCELATION OF THE PRIMORDIAL GRAVITATIONAL ANOMALIES, THAT EXIST IN STRING THEORY AS RESULTS OF THE GREEN-SCHWARTZ ANOMALY CANCELATION MECHANISM. IN THE THESIS, WE WILL ALSO DISCUSS THE GENERATION OF A MASS FOR THE TORSION INDUCED AXIONS, WHICH COULD ACQUIRE THEIR MASSES VIA NON-PERTURBATIVE EFFECTS OF THE CHIRAL ANOMALIES IN THE GLUON SECTOR. IN THE MODERN ERAS, WE SHALL EXAMINE WAYS OF GENERATION OF METASTABLE DE-SITTER PHASES, AGAIN OF RUNNING VACUUM MODEL TYPE, WHICH COULD BE DUE TO A POTENTIAL RESURFACING OF GRAVITATIONAL ANOMALIES, AS A RESULT OF MATTER DEPLETION IN THE CURRENT ERA. A POTENTIAL CHALLENGE IS TO EXPLAIN THE HUGE DIFFERENCE IN THE MAGNITUDE OF THE COSMOLOGICAL CONSTANT TODAY AND DURING INFLATION, IN PARTICULAR IF THE MECHANISM OF CONDENSATES IS COMMON FOR BOTH. |
