Faculty Details

Areas of Interest

• Nuclear Structure
• Renormalization Group approach
• Computational Many-body Physics
• Quantum dynamics
• Entanglement and Many-body systems

Current Research

Nuclear structure has undergone a revolution over the past two decades due to the progress made in developing effective low momentum interactions via the renormalization group evolution. These interactions are either used as inputs in a many-body calculation where medium effects are incorporated. One of the main goals is to study the physics of neutron star governed by the nucleon degrees of freedom, which are the inner layers of the crust and the outer layer of the core of the star. In particular we study superfluidity which is a crucial input for the thermal evolution of the stars and the correct explanation of the glitches. A closely related system that we study is a gas of ultra cold fermions which is backed by a plethora of experiments. In such systems, the scattering length can be tuned via Feshbach resonances to the unitary limit which ressembles the nuclear system which naturally has a large scattering length. A recent direction has been to understand the role played by entanglement in forming bound states in nuclear and atomic systems.

Students

Current PhD Students

• PH19D013    VISWANATHAN PL
• PH20D018    SREELEKSHMI PILLAI (Co-guidance)
• PH18D043    SOUMYABRATA PAUL (Co-guidance)
• PH22D051    ABHAY SINGH RATHORE

Recent Publications

• Equation of state of superfluid neutron matter with low-momentum interactions. V. Palaniappan, S. Ramanan and M. Urban. Phys. Rev. C. 107. 025804.
  DOI: 10.1103/PhysRevC.107.025804. arXiv: https://arxiv.org/pdf/2211.01308.pdf 2023.
• Low-momentum interactions for ultracold Fermi gases. M. Urban and S. Ramanan. Physical Review A. 103 . 063306 . 2021.
• Manifestations of changes in entanglement and onset of synchronization in tomograms . Soumyabrata Paul, S. Lakshmibala, V. Balakrishnan and S. Ramanan . https://arxiv.org/abs/2112.13262 2021.
• Pairing in pure neutron matter. S. Ramanan, M. Urban. EPJ ST (Review). 230 . 567 . 2021.
• Neutron pairing with medium polarization beyond the Landau approximation. M. Urban and S. Ramanan. Physical Review C. 101 . 035803 . 2020.
• Unveiling Regions in multi-scale Feynman Integrals using Singularities and Power Geometry. B. Ananthanarayan, Abhishek Pal, S. Ramanan and Ratan Sarkar. European Physics Journal C. 79 . 1 . 2019.
• Screening and antiscreening of the pairing interaction in low-density neutron matter. S. Ramanan, M. Urban. Physical Review C. 98 . 024314 . 2018.
• Triplet Pairing in Pure Neutron Matter. Sarath Srinivas (IIT M), S. Ramanan (IIT M). Physical Review C. 94 . 064303 . 2016.
• BEC-BCS Crossover in Neutron Matter with Renormalization Group based Effective Interactions,. S. Ramanan (Indian Inst. Tech., Madras), M. Urban (IPN, Orsay),. Phys. Rev. C. 88. 054315 . 2013.
• Local Projections of Low-Momentum Potentials,. K. A. Wendt (OSU), R. J. Furnstahl (OSU), S. Ramanan (Indian Inst. Tech., Madras),. Phys.Rev. C (2012) . 86. 014003. 2012.
• Stringent constraints on the scalar K pi form factor from analyticity, unitarity and low-energy theorems. Gauhar Abbas, B. Ananthanarayan (Bangalore, Indian Inst. Sci.), I. Caprini (Bucharest, IFIN-HH), I. Sentitemsu Imsong, S. Ramanan (Bangalore, Indian Inst. Sci.). 2010. 4 pp. Published in Eur.Phys.J. A (2010) . 44. 175-179. 2010.
• Supersolid in a one-dimensional optical lattice in the presence of a harmonic trap. Tapan Mishra (IIA), Sunethra Ramanan (IISc), Ramesh V. Pai (Goa, U.), Meetu Sethi Luthra (IIA), B. P. Das (IIA. arXiv:1011.2.
  DOI: https://arxiv.org/abs/1011.2523. 1011.2523 523 2010.
• Theory of unitarity bounds and low energy form factors. Gauhar Abbas, B. Ananthanarayan (Bangalore, Indian Inst. Sci.), I. Caprini (Bucharest, IFIN-HH), I. Sentitemsu Imsong, S. Ramanan (Bangalore, Indian Inst. Sci.),. Eur.Phys.J. A (2010) . 45. 389-399. 2010.
• New constraints on the Pion EM form factor using Pi-prime(-Q**2). Gauhar Abbas, B. Ananthanarayan, S. Ramanan (Bangalore, Indian Inst. Sci.). May 22, 2009. 8 pp. Published in Eur.Phys.J. A . 41. 93-100. 2009.
• Constraining the low energy Pion electromagnetic form factor with space-like and phase of time-like data. B. Ananthanarayan, S. Ramanan (Bangalore, Indian Inst. Sci.).. Nov 2008. 8 pp. Published in Eur.Phys.J. C. 60. 73-81. 2009.
• Supersolid and solitonic phases in one-dimensional Extended Bose-Hubbard model. Tapan Mishra, Ramesh V. Pai, S. Ramanan, Meetu Sethi Luthra, B. P. Das,. Phys.Rev.A . 80. 043614. 2009.
• Signatures of the superfluid to Mott insulator transition in cold bosonic atoms in a one dimensional optical lattice. S. Ramanan, Tapan Mishra, Meetu Sethi Luthra, Ramesh V. Pai, B. P. Das. Phys. Rev. A. 79. 013625. 2009.
• Weinberg eigenvalues and pairing with low-momentum potentials. S. Ramanan (Ohio State U. & Bangalore, Indian Inst. Sci.), S.K. Bogner (Ohio State U. & Michigan State U., NSCL & Michigan State U.), R.J. Furnstahl (Ohio State U.).. Sep 2007. 16 pp. Published in Nucl.Phys. A. 797. 81-93. 2007.
• Low-momentum interactions with smooth cutoffs. S.K. Bogner, R.J. Furnstahl, S. Ramanan (Ohio State U.), A. Schwenk (Washington U., Seattle & TRIUMF).. Sep 2006. 29 pp. Published in Nucl.Phys. A. 784. 79-103. 2007.
• Convergence of the Born series with low-momentum interactions. S.K. Bogner, R.J. Furnstahl, S. Ramanan (Ohio State U.), A. Schwenk (Washington U., Seattle).. Feb 2006. 20 pp. Published in Nucl.Phys. A. 773. 203-220. 2006.

Teaching

• 2017 :  (Jan - May) - PH5720 Numerical Methods and Programming Lab; (Jul - Nov) - PH5030 Classical Mechanics / PH5212 Self Study Elective
• 2018 :  (Jan - May) - PH5300 Project II / PH5720 Numerical Methods and Programming Lab; (Jul - Nov) - PH5300 Project II / PH5720 Numerical Methods and Programming Lab
• 2019 :  (Jan - May) - PH5300 Project II / PH5720 Numerical Methods and Programming Lab; (Jul - Nov) - PH5300 Project II / PH5720 Numerical Methods and Programming Lab
• 2020 :  (Jan - May) - PH5300 Project II / PH5720 Numerical Methods and Programming Lab
• 2021 :  (Jan - May) - PH7080 Foundations of Theoretical Physics; (July - Nov) - PH1030 Physics Laboratory I / PH5050 Mathematical Physics II
• 2022 :  (Jan - May) - PH5170 Quantum Mechanics II / PH1040 Physics Laboratory II ; (July - Nov) - PH5050 Mathematical Physics II / PH5060 Physics Lab I (PG) / PH1030 Physics Lab I
• 2023 :  (Jan - May) - PH5170 Quantum Mechanics II