SYMPHY 2016

Abstract: In the last few decades, electronics has become central to our lives thanks to the rapid developments in semiconductor materials and technologies. When I was twenty year old, the only electronics in the house was the radio which worked on vacuum tubes. The invention of the transistor 1947 and later the invention of the integrated circuit changed everything in our lives. An integrated circuit, commonly referred to as chip, may consist of over a billion transistors all of which surprisingly transistors works correctly. Further the developments of semiconductor sensors has made the electronics smart.This has lead to rapid developments in computers, communications entertainment, medicine, defence, and all other aspects of modern life. I will try to bring out the early discovery of semiconductors in 19th century and their evolution over the 20th century.

Abstract: Increasingly, physicists are entering the field of biology, recapitulating the early years of molecular and structural biology, when many among the pioneers were trained physicists who would then go on to make central contributions, even winning Nobel prizes in Biology. Among them were Francis Crick, Max Delbruck, Max Perutz, Maurice Wilkins and a number of others. I will discuss what attracts statistical physicists such as myself to this field, pointing out the gaps in our knowledge of a variety of cellular processes and the need for a better physical understanding of them. A recent article in PLoS Biology had the provocative title: Mathematics Is Biology's Next Microscope, Only Better; Biology Is Mathematics' Next Physics, Only Better. I will try to explain what the author meant, using examples from my own work on the architecture of the cell nucleus, on cellular transport and the modelling of infectious disease.

Abstract: The fundamental constituent of any visible matter are quarks, gluons and leptons. The quarks and gluons are not found to exist in a free state in nature. They are confined inside particles called as hadrons. However they were in a free state in the micro-second old Universe. We will discuss the formation of such a primordial matter in laboratory and its properties. This will lead us to address the question of how does the phase diagram of strong interaction (one of the four basic interactions that occur in nature) look like. We will discuss the recent advances made towards understanding the phase diagram of strong interactions.

Abstract: In this talk I will briefly introduce the LHC (Large Hadron Collider) particle accelerator of the European Organisation for Nuclear Research (CERN) in Geneva, Switzerland. The LHC is the world's largest and most powerful particle accelerator and it will enable scientists to answer some of the most fundamental questions about Nature and our Universe.

Abstract: We all may have seen the following some times: children making soap bubbles or a coffee drop on a plate forming a ring rather than a uniform stain. On the other hand, most of us may not have seen a whisky drop on a plate forming a uniform spot rather than a ring or wine tears in a glass of wine. Yet, all these phenomena are related and have been subject of two recent papers in Physical Review Letters this year (interestingly, formation of soap bubbles using the same model as in one of the Letters was also given as a problem in JEE-2003). In this talk, we discuss interesting physics behind these phenomena with the intention of demonstrating how mundane looking occurrences around us can be used to have fun with physics.

Abstract: Why the Higgs boson mass is at the electroweak scale and not at the GUT or Planck scale constitutes what is called the `hierarchy problem'. I will discuss how attempts to cure this problem have fueled various speculations of physics `Beyond the standard model (BSM)'. I will briefly touch upon the electroweak precision measurements to highlight how we got clues about the Higgs mass from there. Then in specific BSM contexts, I will discuss how fine-tuned supersymmetry is (specifically after the Higgs discovery), and comment on the status of the `alternative' avenues leading to electroweak symmetry breaking (like `little Higgs' or `composite Higgs').

Abstract: Optics is definitely not light work, but a very interesting and highly successful field of serious research. The celebration of year 2015 as the `International Year of Light’ was a global initiative to spread awareness and increase enthusiasm among the students and public in general about the wonderful role of light in our life and work, Science and Technology. The interaction between light and matter plays such an important role in our life that we almost take it for granted. Light helps in a wide range of human endeavour, all the way from deepening our understanding of the Universe to harnessing newer and cleaner sources of energy for the ever-increasing needs of technology. Many of the beautiful objects of nature, such as the peacock feather, butterfly wings and gem stones owe their brilliant color to various optical phenomena arising due to structures of different length scales, at the micro and the nano levels in these objects. Regular extra-thin layered structures with alternating refractive index can give rise to photonic bandgaps, emission enhancement, lossless fiber communication and even reduction in the speed of light! On the other hand, light propagation through random media can lead to new modes of laser action and confinement of photons, revolutionizing biomedical imaging and contributing to the design of economic and nontoxic paints, textiles and displays of brilliant colors. Apart from promising wonderful technological advances, research on light-matter interaction also probes into some very deep secrets of Nature at the conceptual level. Optics is indeed not light work; it involves making light work !

Abstract: Atomic collision physics is closely related to interdisciplinary science. Collisional interactions of fast ions or electrons with clusters and other mesoscopic objects are useful to bridge the gap between gas atoms and bulk solids. A homo-nuclear diatomic molecules, such as, H2 can even be considered as a smallest double-slit to observe Young type electron interference. The complex allotropes of carbon, such as, fullerenes, nanotubes, large organic molecules of biological (DNA bases) interest and PAH molecules have been at the focus of recent atomic collision research. The secondary electron emission from nucleobases and water is an important parameter to estimate the radiation damage caused by fast ions. Atomic processes are influenced when the fast ion passes through a mesoscopic object due to collective plasmon excitation. The C60 fullerene is used as a bench mark system which manifests the giant plasmon resonance. A similar plasmon excitation in the PAH molecules has been demonstrated only recently which will have implications in astrochemistry and plasmon devices.

A recently installed ECR based -ion-accelerator in TIFR and the existing 14 MV Pelletron tandem accelerator are used along with the electron, recoil-ion and high resolution x-ray spectrometers for such experiments to unravel various facets atomic and molecular processes in large biomolecules, fulerenes and clusters.

Abstract: Gravitational waves are generated by accelerated masses, the charge of gravity. Though there are gravitational waves all around us, their amplitude is too small to be detected, except in those rare situations involving stellar mass compact objects like neutron stars or black holes moving very fast. Naturally, such events happen very far from us at extra-galactic distances and reliable detection needs instruments that can measure relative displacement smaller than a billionth of the atomic size. like the advanced LIGO interferometer detectors. Barely a week after they started calibrated stable operation, a few month ago, relatively strong gravitational waves from orbiting and merging binary black holes were detected, marking an impressive beginning for gravitational wave astronomy. I will discuss the physics of gravitational waves and the detectors, and the enhancements that enabled the recent detection. The event also inspired the cabinet approval for the LIGO-India project proposed by the IndIGO Consortium for an identical detector in India, to be operated as part of the gravitational wave detectors network of the next decade.

Abstract: I will summarize the nature of the gravitational wave signal that was recently detected by LIGO. This is the first direct observation of gravitational waves. It was emitted by two colliding black holes 1.3 billion years ago. In addition to discussing the physics of the observed black hole system, I will discuss what might lie ahead for scientists aiming to use gravitational waves to push the frontiers of physics and astronomy.

Abstract: On 2015 September 14, two Laser Interferometric gravitational wave Observatories (LIGO) in the US made the first direct detection of gravitational waves. Detailed analysis showed later that the detected signal was emitted by two black holes which merged to form a single, more massive, black hole. In my talk, I will explain how the detected signal was used to infer important properties of the black holes such as their masses and spins. I will also explain how one could use the detected GW signal to test the correctness of Einstein's general theory of relativity. I will conclude by mentioning some of the exciting things we should be gearing up for when LIGO-like gravitational wave detectors will be improving their sensitivity.