Hello everyone on Blogosphere. It seems like a decade I am away from this blog except to those who are in space or in Miller's planet (courtesy: Interstellar). Coming back here was not a compulsion by the way, but a reflection of the fact that I have been living some beautiful days since November 9 in the city of Joy, Calcutta. The best part of these few days was the freedom I was awarded to do whatever I want which is rare in a government job. I am indeed thankful to my official as well as practical hosts in this city as well as to my university for sending me here. I came here on duty leave taking our students to the National Science Camp held during November 10-12 at Science City here. Although the organizers sent me a hard copy of invitation letter, they simply denied accommodation to me after my arrival, thanks to the lack of communication between national and local organizers. Although they took good care of our students, I had to roam here and there before somehow managing to get into the IACS guest house. Thanks to all who helped me out and gave me a place to stay at night within such a short notice and that too on a weekend. Although the trip to Calcutta started like this, it took off very smoothly as I could utilize my day time reading and discussing things at IACS theoretical physics department. I felt as if I am reading some new science after a long long time. The hectic teaching and administrative work schedule at my workplace hardly allow me to do something creative or read something new. Days were fun with science, whereas the evenings were fun with tasting new food with friends at places like Tandoor Park (Jadavpur), South City Mall (Jadavpur), Peter Cat (Park Street) etc. Visiting the Victoria Memorial at night was simply amazing, such a mesmerizing structure. My stay here also allowed me to watch the new movie Interstellar released last week. This would have never been possible in a small town like Tezpur where I work. Before leaving tonight, just thanking everyone who made my stay comfortable and enjoyable. Also a big thanks to the National Science Camp organizers who could not offer me a place to stay but finally paid for my stay at a place which I am sure is better than anything the organizers would have offered. Adios City of Joy, hope to visit again!
Thursday, November 13, 2014
Wednesday, February 6, 2013
The Physics Department of Tezpur University is organizing National Conference on Theoretical Physics 2013 during February 8-12, 2013 (http://www.tezu.ernet.in/notices/events/nctp12.pdf). This was supposed to happen during October, 2012 but some unavoidable circumstances led to the postponement. In spite of this unfortunate postponement, NCTP 2013 is going to host around hundred participants from different parts of the country including thirteen invited speakers. The topics covered in the invited as well as contributed talks cover almost every area of theoretical physics. Invited speakers include Prof. Amitava Raychaudhuri (Calcutta University), Prof. D P Roy (TIFR), Prof. Rajeev Bhalerao (TIFR), Prof. Raj Gandhi (HRI), Prof. Jayant Murthy (IIA), Prof. Pushpa Khare (IUCAA), Prof. Vinod Krishan (RRI), Prof. Nikhil Chakraborty (SINP), Prof. M. Khan (Jadavpur Univ), Prof. D. K. Choudhury (Gauhati Univ), Prof. N. N. Singh (Gauhati Univ), Prof. Amarjyoti Choudhury (Tezpur Univ) and Prof. S. Ghosh (IIG, Mumbai). The conference is going to take off day after tomorrow with the keynote address by Prof Amitava Raychaudhuri in the afternoon (at 16:30 hrs). From Saturday onwards the technical sessions on Astrophysics, Cosmology, Neutrino Physics, Plasma Physics, Hadron Physics, Computational Physics will start. I hope the participants will find this conference to be of great scientific importance with a pleasant stay at Tezpur.
Wednesday, January 2, 2013
2012 indeed was great (to me at least), not just because the world didn't end on 21st December but for several other reasons, mostly academic though. The year took off while I was in the awesome city of Montreal, Canada. Although it was very cold, watching the snowfall and tasting so many different varieties of wines from different countries were something which made my stay there memorable. I got learn some new physics and could finish some parts of the project before leaving. The most hectic part during the first couple of months of 2012 was to write thesis and apply for postdoc positions. The job market scene was so poor that even after applying for around 40 odd positions trough AJO, I didn't get any positive response. After coming back to India in March, I submitted my thesis in the month of April without too much editing, but thankfully it didn't have to go through too many corrections after reviewer's comments came. I am thankful to the anonymous referee for reviewing my thesis just on time. That enabled my institute to hold my defense just on the deadline (a week before the convocation) and my degree was awarded in the 50th convocation of IIT Bombay. Although I could not attend convocation, getting both Masters and PhD degree was really really huge for me. Another gift from 2012 was the central government job I got in Tezpur University where I am working now. That was a big relief after so many postdoc rejections. It was also like a dream coming true that I got a job in my home state Assam and that too in Tezpur which is just 25 kilometer from my home. I also made my second trip to ICTP for the BENE 2012 workshop, participated in the TeVPA 2012 conference in Mumbai. Not just me, 2012 was a great year for Physics in general. Discovery of Higgs boson at LHC, measurement of non zero reactor mixing angle are undoubtedly the most remarkable things happened in the science this year. I hope similar excitements would continue in the year 2013 as well, may not be from LHC which wont have any proton proton collisions until 2015, but from other experimental frontiers as well related to dark matter, neutrinos and many more. Happy New Year 2013 to all of us!
Friday, December 21, 2012
It was a great day for Physics department of Tezpur University. On the last day of Mayan calender, we organized our first ever in-house symposium. The aim of this symposium was to get familiarize with the works being done in the department by various groups, both experimental as well as theoretical. Since, it was a one day program, we had to stick to just one talk from one group (either by a faculty member or by a research scholar). The program was co-funded by Intellectual Property Rights cell at TU and the inaugural speech was delivered on IPR by an invited speaker. Rest of the day was all about four different sessions (3-4 talks each) followed by poster session by all the research scholars. The event was pretty smooth and we all had a great day for sure. I got reminded of SYMPHY, the in-house symposium we used to organize at IIT Bombay every year. One generic issue which I observed in SYMPHY as well as in today's event is that people get too technical in their talks showing too many plots, technical details and all. That's encouraging for those who are familiar with that particular field, but could yawning for others. May be we should come up with a guideline from next time requesting the speakers to give an overview of the field highlighting the basics as well as theoretical/practical importance so that swallowing it becomes easier for all. Otherwise only few people in the audience will be listening. Good thing about our initiative is that the administration has decided to make such in-house symposium mandatory in all TU departments. Such a practice is very common in well established institutes like IIT Bombay, its really good that a relatively younger department is following those footsteps. Hope this continues every year in future and bring in more collaboration and ideas.
The standard model (SM) of particle physics has crossed another milestone as reported by LHCb collaboration at the recent hadron collider physics symposium held in Kyoto. They have done an incredible measurement of B meson decaying into muon anti-muon pairs. However, people started using this SM milestone as a bullet in SUSY's chest. BBC reported LHCb UK spokesperson saying, "SUSY might not be dead yet, but these results have certainly put her into hospital". And this statement was enough to spark off a debate in the blogosphere followed by couple of arXiv pre-prints. Well, its true that no sign of new physics in this measurement is disappointing, but it amazes me that SUSY has suffered the most whereas there are plenty of other beyond standard model frameworks in the market. I could see three different types of reactions : SUSY is dead or in hospital, SUSY is less natural than thought and SUSY is still alive or in good health. The first reaction is of course a bit harsh and extreme but probably was good for many others who have come up with pre-prints showing available parameter space (natural parameter space probably, I am confused though what to call natural nowadays) which exactly fit these observations. Even if we collect as much data as we want, they will probably never justify the first reaction and at the worst case will leave us with a situation which is a linear combination of the second two reactions.
Sunday, November 11, 2012
Like most of the experimental anomalies and surprises, the Fermi 130 GeV line has also come under dark shadows recently (http://www.newscientist.com/article/dn22466-doubt-cast-on-fermis-dark-matter-smoking-gun.html). It's not that I believed the dark matter interpretation of this line too much, but I still thought this would survive at least for a year ;) This so called game of town in particle astrophysics was initiated by Weniger in April 2012 with a detailed analysis of the publicly available Fermi-LAT data. This was followed by a series of papers from theorists with many well motivated models explaining the origin of this 130 GeV monochromatic line which apparently does not seem to have any obvious astrophysical origin. As the above link to the article in New Scientist says, the Fermi collaboration hasn't denied the presence of this peak in their data, but the dark matter origin of this line is in doubt as the same line is present even when the Fermi detector is pointed towards earth rather than the galactic center (where dark matter is more abundant). Hope Fermi collaboration would soon come up with an official publication telling us more about it. It won't be too much of a surprise if this goes away like B meson anomalies at DO/CDF went away in the wake of LHC results or the phantom of OPERA disappeared after the loose cable connection was found. Nevertheless, one obvious and immediate advantage of these anomalies is that theorists get a chance to write couple of more papers trying to fit their favorite theory or model with the data. Anyways, as someone pointed out correctly at the BENE workshop at ICTP, Trieste two months back, models don't get killed, they sometimes die out of starvation ;-) So even if future Fermi-LAT analysis kills the dark matter interpretation of this interesting gamma ray line, all the models used to explain it already are still in safe heaven. Vive Le Model-Building!
PS: For more information on this doubt cast on Fermi gamma ray line, see RESONANCE blog post!
Monday, November 5, 2012
Pursuing research in an academic institute or university in India is not easy with so much teaching load as well as other administrative works. And probably that's the reason why most of the good research in India are carried out in special research institutes or laboratories where the teaching load is almost zero. This is quite a different picture compared to universities/institutes in other countries (developed ones, in particular) where most of the research output comes from universities. I don't know whom to blame for the poor research conditions of Indian universities, but hopefully the situation will change slowly with the central government authorities seem to be taking a series of initiatives. Anyways, without going further into the blame game, the best way is to make maximum use of the existing system and produce maximum possible quality output. In the physics department of Tezpur University (http://www.tezu.ernet.in/dphy/) where I work, there are around 16 faculty members working in different areas like nano-physics, astrophysics, high energy physics etc. The experimental people are comparatively more active in research as they have a large number of research students under their supervision as well as good number of equipments. Whereas, the members of the theory people do not have many students under them and so is the number of publications. Recently, we have decided to choose a common theme for the theory people so that the theory people can work together on it with a long run perspective. That should hopefully take some load of an individual faculty who do not have the "eligibility" yet to take students under him/her. Here "eligibility" doesn't refer to intellectual eligibility of course, but the "eligibility" criteria defined by the system here which I neither try to justify nor ridicule. But, choosing a common theme of work is not as easy as it may sound, since almost all of us had worked on quite different things during doctoral research. But looking at the fact that the present era is the era of inter-disciplinary research with people explaining condensed matter problems using theory of gravity (just an example), the possible options for such a theme should not be a scarcity.
The expertise the theory people here have are mainly neutrino physics, hadron physics, cosmology, astrophysics/astronomy and plasma physics. As a first trial, we are thinking of considering the problem of dark matter as a common theme (yet to be decided though). Since this is a huge research area, the general feeling is that it should touch upon the field of expertise of each one of us to some extent at least. To go ahead with this theme, it was necessary to highlight some of the interesting and recent things happening in this area to the members since not all of us are actively working on it. I gave an overview seminar on dark matter starting with astrophysical hints like galaxy rotation curve, bullet cluster, structure formation and then going into some details of particle characteristics of dark matter, direct/indirect experimental evidence highlighting many recent anomalies (130 GeV Fermi-LAT line for example) which indirectly point towards the existence of dark matter. Of course, in my ways of looking at this problem, the knowledge of particle physics would be very important to find out the dark matter abundance, its cross section with nuclei in direct detection experiments, the cross section for producing gamma rays or other stuff which we treat as indirect evidence of dark matter etc. One of my colleague here (who specializes in UV astronomy, high energy astrophysics) gave a follow up seminar bringing up an astrophysics problem which could be linked to dark matter in some ways which I do not understand yet. It's about the Missing Baryon problem. This is about the fraction of baryons predicted by big bang nucleosynthesis (BBN) which remain unobserved (about 30% if I am not wrong). Initially I thought this is similar to the Missing Satellite problem which is generic in cold dark matter scenarios which predict more number of satellite galaxies in the clusters which are not observed. Missing Satellite problem can be fixed in scenarios of warm dark matter or non-thermal production of dark matter scenarios well studied in the literature. But this missing baryon problem seems to be different as my colleague says. Its independent of cold or warm dark matter scenarios. Its hard to understand from theory point of view, where those baryons could have gone. Certainly they cant decay into something else, may be BBN scenario has to be modified, but that's also tricky as BBN is one of the very successful predictions of big bang cosmology. I got a Nature news today (http://www.nature.com/nature/journal/v490/n7418/full/490008b.html?WT.ec_id=NATURE-20121004) which talks about a paper claiming that the missing baryons have been spotted in the X-ray data. If confirmed, it would imply that the missing baryons are not exactly missing but just were not being detected somehow. Anyways, it might be too early to settle this mystery and more future data analysis like this group would be needed.