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In these lectures I review the present status of the so-called Standard Cosmological Model, based on the hot Big Bang Theory and the Inflationary Paradigm. I will make special emphasis on the recent developments in observational cosmology,…
Emission and absorption of light lie at the heart of light-matter interaction. Although emission and absorption rates are regarded as intrinsic properties of atoms and molecules, various ways to modify these rates have been sought in…
A group of 72 members of the astrochemistry and spectroscopy communities assembled at Emory University in October, 2012, to discuss the state-of-the art in molecular laboratory spectroscopic techniques used to study molecules of…
In natural light harvesting systems, the sequential quantum events of photon absorption by specialized biological antenna complexes, charge separation, exciton formation and energy transfer to localized reaction centers culminates in the…
First part of a didactic sequence of activities on some topics of Astronomy, related mainly with the day and night cycle and the seasons, including the construction of a simplified solar system model and its use as a resource to discuss…
A bouncing rubber ball under a motion sensor is a classic of introductory physics labs. It is often used to measure the acceleration due to gravity, and can also demonstrate conservation of energy. By observing that the ball rises to a…
Angular momentum is traditionally taught as a (pseudo)vector quantity, tied closely to the cross product. This approach is familiar to experts but challenging for students, and full of subtleties. Here, we present an alternative pedagogical…
Absorption of light by a nanoparticle in the presence of resonant atom and fluorescence of the latter are theoretically investigated. It is shown, that absorption of light by a nanoparticle can be increased by several orders because of…
X-ray spectroscopy offers an opportunity to study the complex mixture of emitting and absorbing components in the circumnuclear regions of active galactic nuclei, and to learn about the accretion process that fuels AGN and the feedback of…
In this astro-particle lecture course I shall try to emphasize evidence of the new physics which we have in cosmological and astrophysical data. This includes support of the inflationary model, necessity of dark energy and of non-baryonic…
A formal derivation is presented of the energy transfer rate between radiation and matter due to the scattering of an isotropic distribution of resonant photons. The derivation is developed in the context of the two-level atom in the…
Beam shaping - the ability to engineer the phase and the amplitude of massive and massless particles - has long interested scientists working on communication, imaging and the foundations of quantum mechanics. In light optics, the shaping…
In this review paper, we present the main aspects of high-energy cosmic neutrino astrophysics. We begin by describing the generic expectations for cosmic neutrinos, including the effects of propagation from their sources to the detectors.…
In the recent years there was published some papers in which the photons are represented as electromagnetic solitons [1,2,3]. All particles - solitons - represent some electromagnetic field restricted in a very small volume, length,…
Astronomical observations in the electromagnetic window - microwave, radio and optical - have revealed that most of the Universe is dark. The only reason we know that dark matter exists is because of its gravitational influence on luminous…
The origin of the ultra high energy cosmic rays (UHECR) with energies above E > 1017eV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. This is a…
Gamma-ray bursts (GRBs) are among the most energetic events in the universe, offering insights into stellar collapse, extreme matter behavior, and cosmic evolution. The advent of multi-messenger astronomy, combining electromagnetic,…
In the past four decades a new type of astronomy has emerged, where instead of looking up into the sky "telescopes" are buried miles underground or deep under water or ice and search not for photons (that is, light), but rather for…
The lack of our knowledge on how angular momentum is transported in accretion disks around black holes has prevented us from fully understanding their high energy emissions. We briefly highlight some theoretical models, emphasizing the…
This work considers the cospectral and arbitrary light emission of a moving source. The observed wavelengths of the emitted photons are described in term of kinematic and dynamical Doppler shifts in which the mass-energy relation plays a…