Sunday, August 23, 2009
তোমাৰ বেদনাত মই কান্দিম
চকুত চকু থৈ একেলগে বাট বুলিম
তোমাৰ হৃদয়ৰ প্ৰতি স্পন্দনত মই থাকিম
তুমিতো কোৱা নাচিলা মই তোমাৰ জোনাক মচি অমাৱস্যাৰ চাদৰেৰে ঢাকিম
দুখৰ কৰণিত ডুবাই ৰাখিম
তুমি হয়তো বুজি উঠিছিলা তুমি নোহোৱা নিশাৰ বেদনা
চকুৰে স্পৰ্শ কৰিব নোৱাৰা মাথোঁ মনেৰে অনুভৱ কৰা এটা এটা নতুন পুৱাৰ ঠিকনা
Thursday, August 20, 2009
1. To explain the slow-roll inflation as well as the origin of quantum fluctuations at the reheat temperature T_R which gives rise to temperature anisotropy in the CMBR they have introduced a new approach incorporating supersymmetry.
2. The inflaton field couples to the supersymmetry breaking sector and its couplings to the MSSM sector is higly suppressed so that quantum corrections don't destroy the slow roll behaviour.
3. Then he discussed the various possible mechanisms of SUSY breaking and also introduced the famous ISS (Intrilligator-Seiberg-Shih) model of dynamical SUSY breaking.
4. Then he used inflaton field as well as the so called "waterfall" field ( I have no idea about the origin of this name) and the interaction of the inflation and SUSY breaking sector via gravity.
5. He showed that such scenario can lead to a long-lived metastable non-SUSY vacuum which could be the true vacuum of our present Universe.
6. He also talks about a distorted version of ISS model where gauge mediation is considered responsible for SUSY breaking. In that case the reheat temperature comes out to be of the order of 1 TeV whereas in the previous case (gravity mediated) it was of the order of 10^9 GeV.
I could not fully understand since I am not familiar with dynamical supersymmetry breaking as well as SQCD where he considered various accidental non-abelian global symmetries which gives rise to an SQCD duality (It basically makes possible to study the theory in both infra-red as well as Ultra-violet limit). Details of his work can be found in the references : Physics Letters B , 660, 236 and JHEP 0904, 092.
Tuesday, August 18, 2009
Monday, August 17, 2009
Sunday, August 16, 2009
Saturday, August 15, 2009
Monday, August 10, 2009
It was the best as well as the longest trekking experience in my life...the trip to Rajmachi fort was simply awesome and will always be as fresh as it is today. We were six people altogether from IIT Bombay. I always prefer to go in a group of less than ten people and six was perfect for me. The trip was fun from the very start..we had to walk almost four kilometres from our hostel to Kanjurmarg Railway station to catch the 0455 hrs local train to Karjat. We walked like anything to reach the station just in time. I wanted to sleep in the train itself since I took a very small nap that night, but that didn't happen. The beautiful landscape on the way to Karjat did not let me sleep at all. We reached Karjat at around 6:30 AM. Then we took auto rickshaw to reach the place which was at the bottom of a hill, in fact that was the place where we started our trekking. The way to Rajmachi from Karjat is not like a normal road..it was just a narrow strip which sometimes become invisible and you may feel like going nowhere. But that's where the fun part of trekking is ;)
We kept going up and up..got lost also in two three places, found a dog as our guide for some part of the journey, got some hints from two-three local people whom we met on the way. Finally at around 11:30 AM we reached the village which is around 100 metre below the fort. We were so tired that we decided to stay there overnight. Since there were no hotels there we approached a family in that village if it would be possible for them to give us a room and food for one night. Fortunately we got a "yes" from them. After taking a little rest and some food we started the second phase of our trek to the forts. There we found lots of other people who had come through the way from Lonavla which is like a proper road. The forts namely Manoranjan and Shree Vardhan were truly amazing. It's hard to believe that people built such huge forts in early days at such a location. We came back from the fort just before nightfall to the house. There was no electriity in that village, they have a solar power system but that operates only in sunny weather. We had nothing to do other than having dinner and then sleeping.
We got up very early in the morning next day since we had to cover the longer route to return from the village. We took the way to Lonavla from the village which was a very easy one with little fun. But the view was superb with lots of waterfalls, rivers in between. We took a bath in one of the rivers, it was really amazing. I never took a bath like that in a river and that too inside a forest, with hills in the surroundings. We kept moving on the way to Lonavla with another dog this time as our guide :D. We reached Lonavla around 1 PM. We were very hungry as well as tired, had lunch there and then took a train back to Bombay. Lonavla was a little scary as we could see lots of people wearing masks ( as a preventive of swine flu). Finally we reached the institute at around 6 PM. I was not being able to make any movement after that..Although it was damn tiring (My muscles are still paining a lot..:( ..) yet the memories will remain evergreen...:)
Friday, August 7, 2009
Tuesday, August 4, 2009
তুমি সাগৰিকা বৰদলৈ কুশলে আছাতো ?
তোমাৰ বাবেই মোৰ শব্দৰ গুহাত গজি উঠে হুমুনিয়াহ
পাণ বজাৰলৈ নাজাবা সন্ধিয়া,
সান্ধ্য আইনেৰে মাতাল দিঘলী পুখুৰীৰ পাৰ
অশ্লীল হৈ পৰিব পাৰে তৰাবোৰ
কিমান অশান্ত বতাহ নিশান্তৰ কামনা
সাগৰিকা, তুমিতো জানাই মই প্ৰেমিক চৰাই
তোমাৰ অভিমানৰ পুখুৰী সিঁচি লৈ আহিম ড'ৰিকণা
মোৰ একোৱাৰিয়ামত নাচিবলৈ
মই ড'ৰিকণা ধৰিবলৈ বৰশী নাবাও
তোমাৰ দুখৰ পোছাক ধুবলৈ মই ধোবাও
তুমি কি ভাল পোৱা গৰমত? চিত্ৰা, মিৰিন্দা নে থামচাপ ?
আমেৰিকা আমাৰ বাবে ঘৃণণীয় শব্দ
ঘোলা পানীত কলেৰা খাই যৌবনপ্ৰাপ্ত মোৰ দেশৰ অযুত শৈশৱ
তুমি কি ভাল পোৱা? মেড'না নে মাইকেল জেকচন
মোক বধিৰ কৰি পেলোৱা সাগৰিকা
Objective: To provide an understanding of the quantum nature of light and to teach how quantum optics serves as a test bed for the foundations of quantum mechanics
Pre-requisite: Course in advanced quantum mechanics
Quantum theory of light: field quantization, lamb shift, quantum beats
Quantum theory of coherence: Photon detection and quantum coherence functions first order coherence and Young’s double source experiment, second order coherence, Physics behind Hanburry-Brown and Twiss experiment, interference of two photons, photon antibunching, Poissonian and sub-Poissonian light, photon counting and photon statistics
Classical and nonclassical light: coherent, Fock and squeezed states of light, coherent state as an eigen state of annihilation operator and as a displaced harmonic oscillator state, properties of coherent state, Physics of squeezed states, squeezed state and uncertainty relation, squeezed coherent state, quadrature variance, multimode squeezing, squeezing via nonlinear optical processes, applications of squeezed states for quantum noise reduction beyond standard shot noise limit
EPR paradox, hidden variables,
Quantum nondemolition (QND) measurement: conditions for QND, QND measurement of photon number by optical Kerr effect and by dispersive atom- field coupling, QND measurement in optical parametric processes
Quantum optical tests of complimentarity: A micro maser which path detector, quantum eraser and quantum optical Ramsey fringes.
We were worried about the course thinking that the instructor may go on teaching stuffs like LASER etc which we had already done last year. But it appears to be quite opposite. The foundation of quantum mechanics is one of the toughest problems yet to be solved completely and lots of research works are still going on. So hopefully this course will give us a good feeling of that field of which we never got any exposure.