Quantum Theory
29-May-2023: Mathematical structure of Quantum Theory reconstructed from Information Principle
Scientists have found the theoretical rationale of the mathematical structure of composite quantum systems consisting of more than one subsystem.
Quantum Mechanics, the theory that describes physical phenomena in microscopic world, was developed in the early 20th century to explain experimental observations like Black-body radiation curve, Photoelectric effect when German physicist Max Planck demonstrated through physical experiments that energy, in certain situations, can exhibit characteristics of physical matter. Later scientists like Albert Einstein, Niels Bohr, Louis de Broglie, Erwin Schrodinger, and Paul M. Dirac advanced Plank’s theory to quantum mechanics–the most accurate mathematical theory of the microscopic world. Unlike other physical theories that are built upon physically motivated postulates, Quantum Mechanics starts with abstract mathematical axioms. For instance, the second postulate of Special Theory of Relativity says that no information can travel faster than like, whereas Quantum Mechanics starts with the axiom that state of a physical system is described by a vector in complex separable Hilbert space.
Yearning for a better physical understanding, scientists are still pursuing their endeavor to re-derive the mathematical structure of quantum theory, starting with physically motivated postulates. During the last quarter of the past century, the advent of quantum information theory appends a new attitude towards this ‘reconstruction program’.
Recently, researchers from S. N. Bose National Centre for Basics Sciences, Kolkata, an autonomous institute of Department of Science and Technology, established an intriguing result in this endeavor. Dr. Manik Banik and his group took the help of a novel information principle, called the principle of Information Causality, to see what kind of descriptions are naturally disallowed for composite quantum systems (that include several quantum objects).
A recent research article published in Physical Review Letters proved that Information Causality plays a crucial role in selecting the quantum composition rule among different mathematical possibilities. In fact, Information Causality can discard a composition rule that is close to our classical worldview in the sense that the resulting theory will allow only classical-like correlations (Bell local correlations). This makes Information Causality champion over the other principles in deriving the mathematical structure of quantum mechanics. The work by Dr. Banik and his group from SNBNCBS thus brings novel physical justification towards the mathematical structure of Quantum Theory.
Borisov
25-May-2023: Indian scientists develop model cosmic dust particles to mimic the unusual polarisation of interstellar comet 2I/Borisov
State of the art visually realistic cosmic dust model created by scientists to replicate the unusual polarisation properties of the first observed interstellar comet (not gravitationally bound to a star), 2I/Borisov, can reproduce experimental as well as observational data of light scattered by dust. The particles would be useful to determine the physical properties of dust present in different regions of space.
Generally, Solar System comets are categorised in two polarimetric classes: low and high polarisation comets depending on the different dust-to-gas ratio observed in the coma. Apart from these two classes, there exists a third class of comets, having polarisation higher than that of high polarisation comets, which was observed only in case of one Solar System comet, C/1995 O1 (Hale-Bopp). Such steep polarimetric slope is believed to occur due to the presence of small pristine cosmic dust. Polarimetric studies of 2I/Borisov, the first interstellar comet to be observed and studied by mankind, exhibited an unusually steeper slope which was observed only in case of one Solar System comet, C/1995 O1 (Hale-Bopp).
To explain the polarimetric observations of comets, it is important to develop realistic computer-modeled dust structures and computationally simulate the scattering of light by such modelled structures.
Recently, scientists from the Indian Institute of Astrophysics (IIA), Bangalore, an autonomous institute of the Department of Science & Technology (DST), Government of India, for the first time developed a visually realistic cosmic dust model using a set of numerical algorithms/software called REST (Rough Ellipsoid Structure Tools). Dr. Prithish Halder, a postdoctoral fellow from IIA, Bangalore, working with Prof. Sujan Sengupta, a scientist at the IIA Bangalore, have crafted surface roughness/irregularities from spheres, superellipsoids and fractal aggregates of spherical grains formed due to coagulation and ballistic agglomeration in the circumstellar or interstellar environment to create the visually realistic cosmic dust particles called agglomerated debris (Solids) and Rough Fractal Aggregates (RFA).
The RFA structures were authenticated by replicating light scattering response of circumstellar/cosmic dust analogs from the Granada Amsterdam Light Scattering Database (a database of light scattering parameters obtained from laboratory simulation of light scattering over dust samples). Once the numerical light scattering simulations over RFA structures successfully reproduced the experimental results, a dust model was prepared considering a mixture of RFA structure and Solid particles over a wide range of sizes from few hundred of nanometers to few micrometers having material composition of amorphous silicate (Forsterite) and amorphous carbon, respectively. The best-fit polarisation and the best-fit polarimetric spectral gradient results were obtained for 80% RFA particles and 20% Solids, indicating the presence of a huge population of highly porous pristine cosmic dust particles. The model results also indicate the observed dust-to-gas ratio is directly proportional to the porous-to-compact ratio of the modelled dust structures. The research has been accepted for publication in The Astrophysical Journal, which is published by the American Astronomical Society (AAS).
AIRAWAT
24-May-2023: AI Supercomputer ‘AIRAWAT’ puts India among top supercomputing league
The AI Supercomputer ‘AIRAWAT’, installed at C-DAC, Pune has been ranked 75th in the world. It was declared so in the 61st edition of Top 500 Global Supercomputing List yesterday at the International Supercomputing Conference (ISC 2023) in Germany. It puts India on top of AI Supercomputing nations worldwide. The system is installed under National Program on AI by Government of India.
“We need to make Artificial Intelligence in India and Artificial Intelligence work for India” – Prime Minister Shri Narendra Modi’s vision “AI FOR ALL”.
Speaking on this achievement, Ministry of Electronics & Information Technology (MeitY) Secretary Shri Alkesh Sharma said, “Artificial Intelligence is the most promising technology in the digital age. India has a strong ecosystem and competitive advantage for AI due to its massive data availability, strong digital economy and skilled workforce. India has been working in the Applied AI with focus on Natural Language Processing, Image Procession, Pattern Recognition, Agriculture, Medical Imaging, Education, Health Care, Audio assistance, Robotics and developing solutions for the strategic sectors.” India will pursue AI technology to empower citizens and organisation to solve the most pressing problems of society and economy to make the world a better place, he added.
President & CEO, NeGD and MeitY Additional Secretary Shri Abhishek Singh stated, “Proof of Concept (PoC) AI Research Analytics and Knowledge Dissemination Platform (AIRAWAT) of 200 AI Petaflops Mixed Precision peak compute capacity is currently funded by MeitY and implemented by C-DAC, Pune. The AIRAWAT PoC of 200 AI Petaflops integrated with PARAM Siddhi – AI of 210 AI Petaflops gives a total peak compute of 410 AI Petaflops Mixed Precision and sustained compute capacity of 8.5 Petaflops (Rmax) Double Precision. The peak compute capacity (Double Precision, Rpeak) is 13 Petaflops.” He added that AIRAWAT is in line with vision of Prime Minister Shri Narendra Modi for the country to enable technology and Artificial Intelligence for the welfare of common people contributing to socio-economic growth of the nation. It may be noted that MeitY has already envisioned roadmap for scaling AIRAWAT to 1,000 AI Petaflops Mixed Precision compute capacity to cater to the current AI computational needs.
Additional Secretary, Meity Shri Bhuvnesh Kumar said, “C-DAC has been pioneer in HPC and AI right from its inception and this entry in the top 500 list is another feather in the cap of C-DAC. The Ministry has always been supporting the implementation of such larger supercomputing systems to accelerate the innovations in science and technology. The C-DAC should enable easy access to such state-of-the-art infrastructure to the Indian community at a nominal cost.”
Ms Kavita Bhatia, Scientist – G and GC (Emerging Technologies), MeitY mentioned, “In alignment with the Atmanirbhar Bharat initiative of Government of India, ‘AIRAWAT’ will empower the Academia, Research Labs, Scientific Community, Industry and Start-Ups to develop indigenous AI enabled products/solutions especially for solving India specific grand challenges complex real-life problems. This AI infrastructure will enable to achieve the vision envisaged under National Program on AI (NPAI).”
Ms Sunita Verma, Scientist – G and GC (R&D in Electronics, IT, AI & ET, Digital Bhashini), MeitY pointed out, “Supercomputing is a core strength of C-DAC. Since the last three and half decades C-DAC has been carrying out R&D in Supercomputing and AI. The MeitY has entrusted C-DAC to deploy the supercomputers under NSM for the Indian scientific and research community. We are making consistent efforts to be at par with the global standards. The system installed at C-DAC Pune shall also be beneficial for Digital India BHASHINI program of the Government.”
Shri E Magesh, Director General, C-DAC said on the feat, “Currently being the fastest Supercomputer in the country, it is designed and architected to be on a scalable infrastructure to act as a common computational cloud platform connecting all Centres of Research Excellence in AI, Indian Centres for Transformational AI, Academic, Research Labs, Scientific Community, Industry and Start-ups. We have initiated the process of on-boarding start-ups and MSMEs working in AI domains in the country.” He congratulated C-DAC, Pune teams led by Col Asheet Kumar Nath, Executive Director, C-DAC, Pune for their excellent efforts to install this system and making it for selection to Top500 List thus making India proud.