Found 24 talks width keyword fundamental physics

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Friday January 27, 2023
Prof. Belén Gavela
IFT/UAM

Abstract

 

 After introducing the concepts of axions and axion-like-particles (ALPs) and their signals, true axions which can be either much heavier or much
lighter than the canonical axion will be discussed. The implications for dark matter, neutron stars and gravitational waves searches will  also be addressed.

 

 


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Thursday January 19, 2023
Prof. José Alberto Rubiño-Martín
IAC

Abstract

I will review the status of the QUIJOTE (Q-U-I JOint TEnerife) experiment, a project led from the IAC with the aim of characterising the polarisation of the Cosmic Microwave Background (CMB) and other galactic or extragalactic physical processes that emit in microwaves in the frequency range 10-42GHz, and at large angular scales (1 degree resolution). QUIJOTE consists of two telescopes and three instruments operating from the Teide Observatory, and started operations about 10 years ago, in November 2012.

I will discuss the status of the project, and I will present the latest scientific results associated with the wide survey carried out with the first QUIJOTE instrument (MFI) at 11, 13, 17 and 19GHz, covering approximately 29000 deg$^2$ with polarisation sensitivities in the range of 35-40 $\mu$K/deg. These MFI maps provide the most accurate description we have of the polarization of the emission of the Milky Way in the microwave range, in a frequency domain previously unexplored by other experiments. These maps provide a unique view of the Galactic
magnetic field as traced by the synchrotron emission. These results have been presented in an initial series of 6 scientific articles published on January 12th, 2023.

Finally, I will describe the prospects for future CMB observations from the Teide Observatory.


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Tuesday September 20, 2022
Dr. Asif ud-Doula
Penn State University

Abstract

Massive stars (at least eight times as massive as the Sun) possess strong stellar winds driven by radiation. With the advent of the so called MiMeS collaboration, an increasing number of these massive stars have been confirmed to have global magnetic fields. Such magnetic fields can have significant influence on the dynamics of these stellar winds which are strongly ionized. Such interaction of the wind and magnetic field can generate copious amount of X-rays, they can spin the star down, they can also help form large scale disk-like structures. In this presentation I will discuss the nature of such radiatively-driven winds and how they interact with magnetic fields.

https://youtu.be/jKmifm17bno


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Tuesday September 13, 2022
Dr. Martín López Corredoira
IAC

Abstract

Cosmological observations (redshifts, cosmic microwave background radiation, abundance of light elements, formation and evolution of galaxies, large-scale structure) find explanations within the standard Lambda-CDM model, although many times after a number of ad hoc corrections. Nevertheless, the expression ‘crisis in cosmology’ stubbornly reverberates in the scientific literature: the higher the precision with which the standard cosmological model tries to fit the data, the greater the number of tensions that arise. Moreover, there are alternative explanations for most of the observations. Therefore, cosmological hypotheses should be very cautiously proposed and even more cautiously received.

There are also sociological and philosophical arguments to support this scepticism. Only the standard model is considered by most professional cosmologists, while the challenges of the most fundamental ideas of modern cosmology are usually neglected. Funding, research positions, prestige, telescope time, publication in top journals, citations, conferences, and other resources are dedicated almost exclusively to standard cosmology. Moreover, religious, philosophical, economic, and political ideologies in a world dominated by anglophone culture also influence the contents of cosmological ideas.


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Thursday May 5, 2022
Dr. Francesca Calore
LAPTh

Abstract

 

In this presentation, I will review the history and literature debate about the anomalous gamma-ray emission detected towards the inner Galaxy by the Fermi-LAT telescope.
The so-called Fermi GeV excess has been first discovered in the early 2010s and later characterised by several, independent, research groups. 
While its main features are well established, the details of its spectral energy distribution and morphology remain debated.
Also the nature of this anomalous signal is unknown. Different interpretations have been put forward and scrutinised.
I will provide an overview of the most promising interpretations in terms of dark matter emission and faint astrophysical sources, and offer an outlook on how we can try to disentangle these two hypotheses with multi-wavelength and multi-messenger astrophysics.

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Thursday June 3, 2021
Dr. Javier Redondo
Universidad de Zaragoza

Abstract

We introduce the strong CP problem and the existence of the Axion as a possible solution. 

We discuss the possibility that axions are the dark matter of the Universe and the possible ways to

detect it or disprove it using: direct laboratory experiments as well as astrophysical and cosmological

arguments. 

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Thursday May 13, 2021
Prof. Diego Blas
Imperial College

Abstract

Bosonic ultra-light dark matter (ULDM) in the mass range m ~ $10^{-22} - 10^{-21} \rm eV$ has been invoked as a motivated candidate with new input for the small-scale `puzzles' of cold dark matter. Numerical simulations show that these models form cored density distributions at the center of galaxies ('solitons'). These works also found an empirical scaling relation between the mass of the large-scale host halo and the mass of the central soliton. We show that this relation predicts that the peak circular velocity of the outskirts of the galaxy should approximately repeat itself in the central region. Contrasting this prediction to the measured rotation curves of well-resolved near-by galaxies, we show that ULDM in the mass range m ~ $10^{-22} - 10^{-21} \rm eV$ is in tension with the data.


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Monday November 17, 2014
Prof. Martín Rivas
Theoretical Physics Department - University of the Basque Country

Abstract

Things should be made simple, but not simpler.

What we want to show is that General Relativity, as it stands today, can be considered as a gravitational theory of low velocity spinless matter, and therefore a restricted theory of gravitation.

Gravity is understood as a geometrization of spacetime. But spacetime is also the manifold of the boundary values of the spinless point particle in a variational approach. Since all known elementary matter, baryons, leptons and gauge bosons are spinning objects, it means that the manifold, which we call the kinematical space, where we play the game of the variational formalism of a classical elementary particle must be greater than spacetime.

Mathematics shows that this manifold for any arbitrary mechanical system is always a Finsler metric space, such that the variational formalism can be interpreted as a geodesic problem on this metric space.

This manifold is just the flat Minkowski space for the free spinless particle.  Any interaction modifies its flat Finsler metric as gravitation does.

The same thing happens for the spinning objects, but now the Finsler metric space has more dimensions and its metric is modified by any interaction, so that to reduce gravity to the modification only of the metric of the spacetime submanifold is to make a simpler theory, the gravitational theory of spinless matter.

Even the usual assumption that the modification of the metric only produces a Riemannian metric of the spacetime is also a restriction because in general the coefficients for a Finsler metric, are also dependent on the velocities. Removal of the velocity dependence of metric coefficients is equivalent to consider the restriction to low velocity matter.

In the spirit of unification of all forces, gravity cannot produce, in principle, a different and simpler geometrization than any other interaction.

References: arXiv: 1203.4076


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Tuesday April 22, 2014
Dr. Martin Stringer
Instituto de Astrofisica de Canarias

Abstract

Any viable theory of the formation and evolution of galaxies should be able to broadly account for the emergent properties of the galaxy population, and their evolution with time, in terms of fundamental physical quantities. Yet, when citing the key processes we believe to be central to the story, we often find ourselves listing from a vast and confusing melee of modelling strategies & numerical simulations, rather than appealing to traditional analytic derivations where the connections to the underlying physics are more tangible. By re-examining both complex models and recent observational surveys in the spirit of the classic theories, we will investigate to what extent the trends in the galaxy population can still be seen as an elegant fingerprint of cosmology and fundamental physics.


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Friday May 27, 2011
Mr. Thomas Herbst
Institute for Quantum Optics and Quantum Information (IQOQI), University of Vienna, Vienna

Abstract

Teleportation of physical objects, transferring from one place to another without passing through intermediate locations, is not possible. However, teleportation of quantum states (the full information of quantum objects) is possible. Quantum teleportation is the faithful transfer of quantum states between systems, relying on the prior establishment of entanglement and using only classical communication during the transmission. In this talk I will first give an introduction of quantum teleportation and then present our on?going free?space quantum teleportation experiment between the two Canary Islands La Palma and Tenerife, separated by 144 km. Our scheme combines a Bell?state measurement, capable to identify two of the four Bell?states, with an actively triggered unitary transformation depending on its outcome. The scheme achieves the optimal teleportation efficiency achievable with linear optical elements. Our work is essential for showing the feasibility of satellite?based experiments and is an important step towards quantum?communication applications on a global scale.


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