Colloquia Archive 2017

The year 2015 has marked the 20th anniversary of the discovery of the top-quark at the Tevatron proton-anti-proton collider at Fermilab near Chicago. The top-quark not only still is the heaviest known elementary particle, but it also interacts through every known fundamental force of nature. It seems surprising that the ...

I will present several models of the effects of electrostatic interactions on viruses. Starting from a discussion of charge distribution and the pertaining charge regulation description, I will explore in detail several examples of the role of charge-charge interactions for capsid stability as well as the interactions between the capsid ...

Number Theory is a subject full of curiosities, amusing problems and compelling challenges. The purpose of the seminar is to explore -- within the context of simple arguments -- the rich and elegant interplay that exists between the realms of numbers and the world of quantum mechanics. In particular we discuss the ...

String theory is the evolution of theoretical constructions developed during the past century, embracing and extending general relativity and quantum mechanics. One of the lessons of string theory has been the discovery of relationships between seemingly different theories, called dualities. In particular, the gauge/gravity duality postulates that a theory ...

With the discovery of a Higgs like scalar in 2012 at the LHC, and the lack of discovery of beyond the Standard Model states with masses proximate to the electroweak scale, it is clear that new theoretical approaches to interpreting the ever growing LHC data set are of very great ...

Since the standard cosmological model is such a good fit to the cosmic microwave background anisotropy data, a great deal of attention has focused on any signs of "physics beyond the standard model". One particular large-scale "anomaly" that has been noted is that there appears to be more power on ...

I will describe the theoretical interest in large-field inflation and its relation to potential future observations, e.g. through primordial gravitational waves. I will outline the possible fundamental obstructions to realizing such inflationary scenarios, both in string theory and in quantum gravity in general. The focus will in particular be ...

I introduce the key techniques used to model the dynamics of galaxies and illustrate how these method have contributed to our understanding of the mechanism by which galaxies form and evolve.

The recent development of methods of conferring well-defined shape and interaction anisotropies to Brownian colloidal particles renders their phase behavior and dynamics closer to that of molecules, but on greatly expanded spatial and temporal scales. We focus here especially on interaction anisotropy, which is present in the simplest form in ...

After the completion of the Standard Model (SM) through the Higgs discovery particle physicists are waiting for the discovery of new particles either directly with the help of the Large Hadron Collider (LHC) or indirectly through quantum fluctuations causing certain rare processes to occur at different rates than predicted by ...

Paul Dirac proposed the baryon symmetric universe in 1933. This proposal has become very attractive now, since it seems that all pre-existing asymmetry would have been diluted if we had an inflationary stage in the early universe. However, if our universe began baryon symmetric, the tiny imbalance in numbers of ...

In the past statistical physics and elementary particle physics have had many interesting interactions and various topics have been held in common. We have in mind studies of phase transitions and symmetry breaking, the renormalization group and universality, or the Gibbs formalism itself which is also the underlying structure of ...

Stars and star clusters are the fundamental visible building blocks of galaxies at present days as well as in the early universe. They form by gravitational collapse in regions of high density in the complex multi-phase interstellar medium. The process of stellar birth is controlled by the intricate interplay between ...

The spectral gap - the difference in energy between the ground state and the first excited state - is of central importance to quantum many-body physics. It determines the phase diagram at low temperature, with quantum phase transitions and critical phenomena occurring when the gap vanishes. Some of the most challenging and ...

In view of future high-statistics data, it is useful to define a framework for precise determinations of the properties of the Higgs particle valid in generic extensions of the Standard Model. As I will discuss, this goal can be achieved with a limited set of so-called "Pseudo-Observables" (PO). The PO ...

Among the many exotic properties of topological superconductors, the prediction that they can host Majorana fermions stands out both for its fundamental interest and for possible applications in topological quantum computing. To exchange (braid) pairs of Majoranas is the heroic experiment, since it would identify them as a fundamentally new ...

I will talk about a way to compute transition probabilities that works directly that the level of probabilities and not amplitudes. The formalism guarantees that the initial and final states are always linked by a chain of retarded propagators and it has a nice diagrammatic approach.