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Dark energy

The dominant and most mysterious ingredient of the current standard model, is, without doubt, the so-called dark energy, that contributes about 75% of the mass/energy density of the Universe, and causes the current accelerating expansion. The most direct evidence for this acceleration comes from the observation of "standard candles" at cosmological distances, or rather objects whose intrinsic luminosities can be calibrated a priori, so that their distance can be measured via their apparent luminosity. The so-called type Ia supernovae have been used in this way, and at the end of the '90s allowed the acceleration to be detected for the first time. Current and future research will concentrate on identifying a time dependence on the so-called "equation of state" of dark energy, to demonstrate whether dark energy is simply Einstein's cosmological constant, or if it is connected to a primordial energy field also related to the formation of elementary particles. To this end, various projects either underway or proposed for the future, are dedicated to systematic searches for type Ia supernovae, both from the ground and space. These will surely greatly increase the volume of data on distant SNe, shedding new light on the nature of cosmic acceleration. The search for and the calibration of new standard candles (such as "core-collapse" SNe and gamma-ray bursts) are also areas of research receiving growing attention.

 

Other experiments plan to cover large areas of the sky with high quality images (and so in general observed from space) to measure so-called weak lensing. This distortion, introduced in the images of "background" galaxies by the mass distribution along the path that the photons travel to reach us, depends on the gravitational growth of fluctuations, and ultimately on the cosmological parameters. The final goal of these surveys is make maps of the "shear", as the weak lensing deflection is called, in various redshift intervals and reproduce the tomographic distribution of cosmic structure at successive epochs. These "tomographic plates" directly measure the expansion and structure growth history of the Universe that depend directly on the presence of dark energy.

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ASTRI: a new pathfinder of the arrays of Cherenkov telescopes

Jun 13, 2019

ASTRI: a new pathfinder of the arrays of Cherenkov telescopes On June 12nd 2019, in La Laguna (Tenerife, Spain) Prof. Nichi D’Amico, President of the Italian National Institute for Astrophysics (INAF), and Prof. Rafael Rebolo Lopez, Director of the Instituto de Astrofisica de Canaries, signed a Record of Understanding to enter a detailed negotiation on a technical and programmatic basis aimed to install and operate the ASTRI Mini-Array at the Observatorio del Teide

Giant planets and comets battling in the circumstellar disk around HD 163296

May 23, 2019

Giant planets and comets battling in the circumstellar disk around HD 163296 In a study appearing today on The Astrophysical Journal, an INAF-lead team of researchers explored whether the anomalous features in the dust and gas distributions of HD 163296's disk revealed by ALMA's observations could arise from the interaction of the giant planets with a component of the disk previously unaccounted for: the planetesimals

Particle Acceleration and Transport: from the Sun to Extragalactic Sources

Nov 09, 2018

Particle Acceleration and Transport: from the Sun to Extragalactic Sources 12-16 November 2018, Università della Calabria, Rende, Italy