N.D. Hari Dass earned his PhD from the University of California, Santa Barbara, and has since conducted research and taught at prestigious institutions worldwide, including the University of California, Los Angeles, the Max Planck Institute for Physics in Munich, the Niels Bohr Institute in Copenhagen, CERN in Geneva, NIKHEF in Amsterdam, the Universities of Utrecht and Amsterdam, and KEK in Japan. He has also worked in India at the Raman Research Institute, Institute of Mathematical Sciences, Indian Institute of Science, Chennai Mathematical Institute, and Tata Institute of Fundamental Research.Prof. Hari Dass is a Fellow of the National Academy of Sciences in India and has published over 60 peer-reviewed articles on his research areas, which include lattice gauge theory, quantum field theory, gravitation and astrophysics, and foundations of quantum mechanics. He has extensive teaching experience at the undergraduate and graduate levels in both the USA and India.He is the author of the book "The Principles of Thermodynamics" (CRC Press, 2013), and the revised edition "The Essentials of Thermodynamics" (SRI Books, 2021).

• Strings.- Quantisation of NNS strings.- Problems with NNS strings.- Quark Model.- Yang-Mills eld theories and their quantisations.- Quantum Chromodynamics.- Perturbative QCD.- Problem of unobserved quarks.- Lattice Gauge Theories.- Dual formulations of lattice gauge theories.- Probing quark connement.- Nambu's formal mapping between Wilson Loops and Strings.- The Multilevel Algorithm.- The exact spectrum of bosonic strings.- Numerical simulations.- Results for d = 3SU(2).- Results for d = 4SU(3).- Polchinski-Strominger eective string theories.- PS effective strings to higher orders.- A 2-d QFT Perspective.- Eective string theories in other gauges.- Related Issues: AdS/CFT approaches.- Concluding remarks.

N.D. Hari Dass earned his PhD from the University of California, Santa Barbara, and has since conducted research and taught at prestigious institutions worldwide, including the University of California, Los Angeles, the Max Planck Institute for Physics in Munich, the Niels Bohr Institute in Copenhagen, CERN in Geneva, NIKHEF in Amsterdam, the Universities of Utrecht and Amsterdam, and KEK in Japan. He has also worked in India at the Raman Research Institute, Institute of Mathematical Sciences, Indian Institute of Science, Chennai Mathematical Institute, and Tata Institute of Fundamental Research.Prof. Hari Dass is a Fellow of the National Academy of Sciences in India and has published over 60 peer-reviewed articles on his research areas, which include lattice gauge theory, quantum field theory, gravitation and astrophysics, and foundations of quantum mechanics. He has extensive teaching experience at the undergraduate and graduate levels in both the USA and India.He is the author of the book "The Principles of Thermodynamics" (CRC Press, 2013), and the revised edition "The Essentials of Thermodynamics" (SRI Books, 2021).

• Strings.- Quantisation of NNS strings.- Problems with NNS strings.- Quark Model.- Yang-Mills eld theories and their quantisations.- Quantum Chromodynamics.- Perturbative QCD.- Problem of unobserved quarks.- Lattice Gauge Theories.- Dual formulations of lattice gauge theories.- Probing quark connement.- Nambu's formal mapping between Wilson Loops and Strings.- The Multilevel Algorithm.- The exact spectrum of bosonic strings.- Numerical simulations.- Results for d = 3SU(2).- Results for d = 4SU(3).- Polchinski-Strominger eective string theories.- PS effective strings to higher orders.- A 2-d QFT Perspective.- Eective string theories in other gauges.- Related Issues: AdS/CFT approaches.- Concluding remarks.

N.D. Hari Dass earned his PhD from the University of California, Santa Barbara, and has since conducted research and taught at prestigious institutions worldwide, including the University of California, Los Angeles, the Max Planck Institute for Physics in Munich, the Niels Bohr Institute in Copenhagen, CERN in Geneva, NIKHEF in Amsterdam, the Universities of Utrecht and Amsterdam, and KEK in Japan. He has also worked in India at the Raman Research Institute, Institute of Mathematical Sciences, Indian Institute of Science, Chennai Mathematical Institute, and Tata Institute of Fundamental Research.Prof. Hari Dass is a Fellow of the National Academy of Sciences in India and has published over 60 peer-reviewed articles on his research areas, which include lattice gauge theory, quantum field theory, gravitation and astrophysics, and foundations of quantum mechanics. He has extensive teaching experience at the undergraduate and graduate levels in both the USA and India.He is the author of the book "The Principles of Thermodynamics" (CRC Press, 2013), and the revised edition "The Essentials of Thermodynamics" (SRI Books, 2021).

• Strings.- Quantisation of NNS strings.- Problems with NNS strings.- Quark Model.- Yang-Mills eld theories and their quantisations.- Quantum Chromodynamics.- Perturbative QCD.- Problem of unobserved quarks.- Lattice Gauge Theories.- Dual formulations of lattice gauge theories.- Probing quark connement.- Nambu's formal mapping between Wilson Loops and Strings.- The Multilevel Algorithm.- The exact spectrum of bosonic strings.- Numerical simulations.- Results for d = 3SU(2).- Results for d = 4SU(3).- Polchinski-Strominger eective string theories.- PS effective strings to higher orders.- A 2-d QFT Perspective.- Eective string theories in other gauges.- Related Issues: AdS/CFT approaches.- Concluding remarks.