One of the most successful theory describing cosmic objects, their interactions and their time evolution, is the Einstein’s theory of Gravity. One of the main prediction of the Gravity theory is the existence of Gravitational Waves (GW), the ripples of space-time. The latest GW detections by ground-based interferometers and the discovery of a binary pulsar whose orbital period changes in accordance with the predicted GW emission, verified the predictions of the Einstein’s theory and opened up an intensive activity of understanding all aspects of the GWs and the implications of this discovery to alternative theories of Gravities and their Cosmological implications.

The modified gravity theories can give us important information on the structure and properties of the compact objects predicted by these theories and also the observational signatures which they can introduce. It is expected that future ground and space-borne detectors will improve our perception of gravitational interactions in particular will shed light into the existence of exotic compact objects, like hairy black holes and wormholes. These compact objects provide a window into the microscopic structure of spacetime in Quantum Gravity and the hope is to understand the nature of their interior, potential applications to Quantum Cosmology, and the development of further connections to quantum information and laboratory quantum simulation. The formation of these compact objects may also trigger possible holographic phase transitions to other compact objects.

The aim of the 12th Aegean Summer School is to discuss the recent developments in theory in Gravity and Cosmology and in observations discussing the LIGO, VIRGO, LISA and BINGO experiments.

The 12th Aegean Summer School will take place in the town of Apollonia in the island of Sifnos, in the Cultural Centre “Marianthi Simou” and it is organized and sponsored by the National Technical University of Athens, Greece, the University Paris-Sud, Orsay, France, the University of Tuebingen, Germany, the University Nottingham, England, the University Sapienza, Rome, Italy, the University Pontificia Universidad Católica de Valparaiso, Chile, Universidad Central de Chile, Santiago, Chile, the University Sao Paulo, Brazil and the European Cooperation in Science and Technology (COST).