Alain Picard The reionization of the primordial universe is a crucial step in cosmic evolution that occurs after the Dark Age, a period during which the cosmic atmosphere was dominated by opaque neutral hydrogen. This phenomenon reflects the gradual transition of this dark universe to a lit and ionized environment through the emergence of the first stars … Read more
Baryonic acoustic oscillations (BAO) represent a fundamental phenomenon in cosmology, marking a crucial sequence in the history of the Universe. These primordial sound waves, which occurred in the hot plasma composed of baryons and photons, have left indelible traces visible in the large-scale structure of the Universe. By studying these oscillations, astrophysicists gain access to … Read more
Observations of the cosmos reveal mysteries that are intricately woven into the delicate fabric of the primordial universe. Among these invisible footprints, the Sachs-Wolfe effect holds a prominent place. It traces the memory of gravitational evolution through the anisotropies of the cosmic microwave background, this ancient breath imbuing every photon of the cosmic background radiation. … Read more
Black holes embody one of the deepest mysteries of the universe, revealing both the extreme power of gravity and the limits of current physics. These celestial objects, formed from the collapse of massive stars, concentrate an incredible mass into an infinitely small space. As a result, they become natural laboratories where quantum gravity and quantum … Read more
Magnetic monopoles are among the most fascinating enigmas of modern physics, captivating both astrophysicists and particle physics theorists. At the heart of contemporary cosmology, these hypothetical particles dissociate classical magnetic duality by postulating the existence of objects carrying a unique magnetic pole, as opposed to the familiar dipoles of conventional physics. Their discovery would transform … Read more
The violation of CP symmetry (charge-parity) remains one of the most fascinating and complex phenomena studied in modern cosmology. Since its discovery in the decays of K mesons in the 1960s, this anomaly challenges the fundamental equality between matter and antimatter in the primordial universe. While classical theories assumed a perfect balance between particles and … Read more
The matter-antimatter asymmetry in the Universe remains a fascinating enigma in cosmology and fundamental physics. While the Standard Model predicts a symmetric creation of matter and antimatter during the Big Bang, our observations show a striking predominance of matter in the current Universe. This imbalance raises profound questions about the nature of physical laws, the … Read more
In the rapidly expanding field of high-energy physics, supersymmetry stands out as a revolutionary approach aimed at surpassing the limits of the standard model. This theory proposes that every fundamental particle, whether a fermion or a boson, has a supersymmetric partner whose spin differs by half a unit. Moreover, recent advancements in the detection of … Read more
Recent advances in fundamental physics shed light on a fascinating concept that goes beyond the simple perception of the three-dimensional universe: the existence of extra dimensions. These dimensions, invisible to the naked eye and conventional instruments, could radically transform our understanding of space-time and thus revolutionize the field of astronomy. At the heart of the … Read more
Since the 1970s, the study of black holes has profoundly transformed the understanding of entropy, a fundamental concept in thermodynamics, by tying it to the most mysterious astrophysical objects in the universe. The revelation that these strange regions of spacetime can possess entropy, measuring the amount of information they contain, has not only opened new … Read more