Found 5 talks width keyword diffuse radiation

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Thursday July 21, 2011
Dr. Martín Lopez Corredoira
Instituto de Astrofísica de Canarias, Spain

Abstract

I will review some theoretical ideas in Cosmology different to the standard "Big Bang": the Quasi-steady State model, Plasma Cosmology model, non-cosmological redshifts, alternatives to non-baryonic dark matter and/or dark energy, and others. Some open problems of Cosmology within the standard model will also be summarized.


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Wednesday July 20, 2011
Dr. Miguel Ángel Sánchez Conde
Instituto de Astrofísica de Canarias, Spain

Abstract

What's the dark matter made of? Do we have any idea of the kind of particle that should constitute ~85% of the matter content of the Universe? In this talk, I will briefly explain the properties that such a particle might have and will present some of the proposed candidates that arise from beyond the Standard Model of particle physics. Next stop will be to give an overview of the present status of dark matter searches, mainly focusing on gamma-rays. There is a tremendous effort currently ongoing that involves an impressive battery of experiments both at the lab and observatories around the world.
In a second part,  the importance of N-body cosmological simulations for the understanding of how dark matter halos form and evolve from the early Universe will be discussed. At this point, some problems arise that it's worth mentioning and that will hopefully lead to debate.

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Tuesday July 19, 2011
Dr. Ricardo Tanausu Génova Santos
Instituto de Astrofísica de Canarias, Spain

Abstract

In the first part of this talk I will present a historical review of the CMB observations, one of the most powerful cosmological probes. Following the first talk of this series, where Jose Alberto described the basic parameters that define the standard cosmological model, I will here summarize the constraints to these parameters that have been derived from these observations. I will also describe the current challenges in this field, in particular the detection of the inflation's B-mode signal through CMB polarization observations, as well as the experiments that have been developed worldwide to this aim, including IAC's QUIJOTE. In the second part, I will focus on the so-called ``missing baryon problem'', i.e. the fact that the half of the expected baryon content of the local universe remains yet undetected. I will describe the theoretical studies that provide hints on where these baryons could be located, and the observational efforts that have been undertaken in this regard.


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Monday July 18, 2011
Dr. José Alberto Rubiño
Instituto de Astrofísica de Canarias, Spain

Abstract

This is the first talk of a series of four aimed to discuss about Cosmology. Here, I will review the basic concepts of the standard cosmological model, which will be further discussed in the following talks, as well as the observational evidence in support of the Lambda-CDM model. As the subject is very broad, I will focus the discussion on topics related with inflation, dark matter and dark energy. Moreover, I will mainly discuss large scale structure probes.


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Thursday April 28, 2011
Dr. Alberto Dominguez Diaz
Instituto de Astrofísica de Andalucia, Spain

Abstract

The extragalactic background light (EBL) is of fundamental importance both for understanding the entire process of galaxy evolution and for gamma-ray astronomy, but the overall spectrum of the EBL between 0.1 and 1000 microns has never been determined directly from galaxy spectral energy distribution (SED) observations over a wide redshift range. Galaxy SED-type fractions from z=0.2-1 are estimated from a multi-wavelength sample from the AEGIS collaboration that allows a new determination of the evolving EBL. Then, the transparency of the Universe to very high energy (VHE) gamma-ray photons is derived. We find the maximum transparency of the Universe allowed by the standard framework. This result challenges current VHE observations of high redshift blazars. A solution to this problem is discussed utilizing VHE spectra of the highest redshift blazars assuming the existence of a plausible dark matter candidate known as axion-like particle.


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