Colloqui della Classe di Scienze
Nel corso di ogni Anno Accademico la Scuola Normale Superiore organizza nella Sala degli Stemmi del Palazzo della Carovana, un ciclo di seminari dal titolo "Colloqui della Classe di Scienze".
Questi Seminari, che hanno cadenza approssimativamente mensile, sono tenuti da specialisti di livello internazionale, e sono dedicati a tematiche di interesse generale per la Biologia, la Chimica, la Fisica e la Matematica.
Le tematiche affrontate e la presentazione dei contenuti sono accessibili ad un ampio pubblico, in modo da fornire delle occasioni di incontro e discussione per studenti, borsisti, visitatori, ricercatori e docenti della Classe, e per quanti altri fossero interessati a partecipare.
Anno Accademico 2012 - 2013
Damiano Brigo, Imperial College, London, UK
Mercoledì 16 ottobre 2013, ore 15:00 (Sala Azzurra, Palazzo Carovana)
The ongoing revolution in financial modeling and the possible end of platonic pricing: a stochastic analysis approach to credit and funding liquidity risk
The market for financial products and derivatives reached an outstanding notional size of 708 USD Trillions in 2011, amounting to ten times the planet gross domestic product. Even discounting double counting, derivatives appear to be an important part of the world economy and have played a key role in the onset of the financial crisis in 2007. We introduce the Nobel-awarded option pricing paradigm by Black Scholes and Merton, hinting at precursors such as Thales, Bachelier and De Finetti. We explain how the self financing condition coupled with Ito's formula lead to the Black Scholes Partial Differential Equation (PDE) for basic option payoffs. We hint at the Feynman Kac theorem that allows to interpret the Black Scholes PDE solution as the expected value under a risk neutral probability of the discounted future cash flows, presenting the detailed solution for Call Options on equity, and highlighting the fundamental fact that the option price does not depend on the expected rate of return of the related underlying asset. Finally, we embed this theory in the recent financial landscape, re-discuss its assumptions and present a high level view of current issues in financial modeling, especially funding liquidity costs and credit risk, leading to an intuitive description of Nonlinear PDEs, recursive equations and Backward Stochastic Differential Equations (BSDEs). In a provocative conclusion, the challenges of recursive, holistic and aggregation-dependent nonlinear pricing algorithms are highlighted, and we explain how this may finally relegate Platonic pricing to history books, an awareness that, ironically, industries different from the financial one have shown for a long time.
Anno Accademico 2013 - 2014
Eiichiro Komatsu, Max-Planck-Institut für Astrophysik, Garching
Mercoledì 6 novembre 2013, ore 15:00 (Sala Azzurra, Palazzo Carovana)
Critical Tests of Theory of the Early Universe using the Cosmic Microwave BackgroundAbstract:
The Cosmic Microwave Background (CMB), the fossil light of the Big Bang, is the oldest light that one can ever hope to observe in our Universe. The CMB provides us with a direct image of the Universe when it was still an "infant" - 380,000 years old.
The Wilkinson Microwave Anisotropy Probe (WMAP) has mapped the microwave sky in five frequency bands for nine years since 2001, creating a full-sky CMB map with the unprecedented precision. The WMAP data have enabled us to obtain a wealth of cosmological information, such as the composition, age, geometry, and history of the Universe. Yet, can we go further and learn about the primordial universe, when it was much younger than 380,000 years old, perhaps as young as a tiny fraction of a second? If so, this gives us a hope to test competing theories about the origin of the Universe at ultra high energies. In this talk, we will review the physics of CMB and the WMAP mission, present the basic results from nine years of observations, and discuss their cosmological implications. We will also comment on the recent results reported by the Planck mission.
Massimo Olivucci, Chemistry Department,Bowling Green State University,Bowling Green, OH 43403 (USA) Dipartimento di Biotechnologie, Chimica e Farmacia, Università degli Studi di Siena, 53100 Siena (Italy)
Mercoledì 18 dicembre 2013, ore 15:00 (Sala Stemmi, Palazzo Carovana)
From Computational Photobiology to the Design of Vibrationally Coherent Molecular Devices and Motors
In the past multi-configurational quantum chemical computations coupled with molecular mechanics force fields have been employed to investigate spectroscopic, thermal and photochemical properties of visual pigments. Here we show how the same computational technology can nowadays be used to design, characterize and ultimately, prepare light-driven molecular switches which mimics the photophysics of the visual pigment rhodopsin (Rh) displayed in Figure A. When embedded in the protein cavity the chromophore of Rh undergoes an ultrafast and coherent photoisomerization. In order to design a synthetic chromophore displaying similar properties in common solvents, we recently focused on indanylidene-pyrroline (NAIP) systems. We found that these systems display light-induced ground state coherent vibrational (Figure B) motion similar to the one detected in Rh. Semiclassical trajectories provide a mechanistic description of the structural changes associated to the observed coherent motion which is shown to be ultimately due to periodic changes in the π-conjugation.
Atac Imamoglu, Institute of Quantum Electronics, Department of Physics, ETH Zurich, HPT G12 8093 Zurich, Switzerland
Mercoledì 15 gennaio 2014 ore 15:00 (Sala Stemmi)
Interfacing single photons and condensed-matter systems
There are two complementary approaches for investigating quantum optical phenomena in the solid-state. The first approach exploits the superior optical properties of solid-state emitters and the possibility of integrating them in photonic nanostructures, for realizing indistinguishable single-photon sources, all-optical spin manipulation as well as demonstration of a quantum interface between flying photonic qubits and stationary spin qubits. The second approach uses quantum optical techniques such as cavity quantum electrodynamics or photon correlation measurements as novel spectroscopic tools for studying many-body phenomena such as the Fermi-edge singularity or the quantum Hall effect. In this talk, I will describe recent experiments addressing these new frontiers at the intersection of quantum optics, condensed-matter physics and quantum information processing.
Giuseppe Mussardo, SISSA, Trieste
Mercoledì 5 febbraio 2014, ore 15:00 (Sala Stemmi)
Quantum Quench Dynamics
I will discuss in simple terms some topics emerging from recent studies of quantum systems driven away from equilibrium. Particular emphasis will be given to the integrable/non-integrable nature of the Hamiltonian and to its local properties.
Jason Chin, MRC Laboratory of Molecular Biology
Giovedì 19 giugmo 2014, ore 15:00 (Sala Azzurra)
Reprogramming the Genetic Code
The information for synthesizing the molecules that allow organisms to survive and replicate is encoded in genomic DNA. In the cell, DNA is copied to messenger RNA, and triplet codons (64) in the messenger RNA are decoded - in the process of translation - to synthesize polymers of the natural 20 amino acids. This process (DNA RNA protein) describes the central dogma of molecular biology and is conserved in terrestrial life. We are interested in re-writing the central dogma to create organisms that synthesize proteins containing unnatural amino acids and polymers composed of monomer building blocks beyond the 20 natural amino acids. I will discuss our invention and synthetic evolution of new 'orthogonal' translational components (including ribosomes and aminoacyl-tRNA synthetases) to address the major challenges in re-writing the central dogma of biology. I will discuss the application of the approaches we have developed for incorporating unnatural amino acids into proteins and investigating and synthetically controlling diverse biological processes, with a particular emphasis on understanding the role of post-translational modifications.
Anno Accademico 2014 - 2015
Michele Vendruscolo, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
Mercoledì 18 febbraio 2015, ore 15:00 (Sala degli Stemmi)
Physical principles of protein aggregation
I will discuss the extent to which the aggregation process of proteins is related to the physico-chemical properties of their amino acid sequences. Based on these properties, it is possible to develop methods for the prediction of the aggregation propensities of proteins. I will then illustrate how these methods can be of practical interest and importance in biotechnology and medicine.
Giovanni Forni, University of Maryland
Mercoledì 3 giugno 2015, ore 15:00 (Sala degli Stemmi)
Sulla dinamica dei biliardi poligonali
Ci proponiamo di passare in rassegna alcuni dei risultati più salienti e alcune idee guida nello studio della dinamica dei biliardi poligonali. Un biliardo poligonale e' un sistema dinamico dato dal moto di un punto materiale (o di un raggio luminoso) in un poligono piano con collisioni elastiche (riflessione) ai bordi. Nel caso particolare in cui gli angoli siano razionali (misurati in radianti), la dinamica di questi biliardi è legata a quella degli scambi di intervalli e dei cosiddetti flussi di traslazione la cui teoria ha avuto uno sviluppo eccezionale negli ultimi decenni (con contributi fondamentali di matematici premiati dalla medaglia Fields, da M. Kontsevich C. McMullen e J.-C. Yoccoz a A. Avila e M. Mirzakhani). Nel caso generale (non-razionale) i progressi sono stati molto meno eclatanti tanto che le principali questioni sono state inlcuse da A. Katok in un lista dei 5 problemi più resistenti della dinamica. Per esempio, nonostante i risultati recenti (R. Schwartz, P. Hooper) sul problema dell'esistenza di orbite periodiche nei triangoli, non si sa se ogni triangolo acutangolo abbia un'orbita periodica diversa dall'orbita dovuta a Giovanni Fagnano (1775).
Anno Accademico 2015 - 2016