What is Shankar: Definition and 47 Discussions

Ravi Shankar (Bengali pronunciation: [ˈrobi ˈʃɔŋkor]; born Robindro Shaunkor Chowdhury, spelled Ravindra Shankar Chowdhury in Sanskrit; 7 April 1920 – 11 December 2012), whose name is often preceded by the title Pandit (Master), was an Indian sitar virtuoso and a composer. He became the world's best-known exponent of North Indian classical music, in the second half of the 20th century, and influenced many other musicians throughout the world. Shankar was awarded India's highest civilian honour, the Bharat Ratna, in 1999.
Shankar was born to a Bengali Brahmin family in India, and spent his youth as a dancer touring India and Europe with the dance group of his brother Uday Shankar. He gave up dancing in 1938 to study sitar playing under court musician Allauddin Khan. After finishing his studies in 1944, Shankar worked as a composer, creating the music for the Apu Trilogy by Satyajit Ray, and was music director of All India Radio, New Delhi, from 1949 to 1956.
In 1956, Shankar began to tour Europe and the Americas playing Indian classical music and increased its popularity there in the 1960s through teaching, performance, and his association with violinist Yehudi Menuhin and Beatles guitarist George Harrison. His influence on Harrison helped popularize the use of Indian instruments in Western pop music in the latter half of the 1960s. Shankar engaged Western music by writing compositions for sitar and orchestra, and toured the world in the 1970s and 1980s. From 1986 to 1992, he served as a nominated member of Rajya Sabha, the upper chamber of the Parliament of India. He continued to perform until the end of his life.

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  1. kmm

    I Shankar on constraints and free parameters for a particle in a box

    On page 160 in Shankar, he discusses how we get quantized energy levels of bound states - specifically for the particle in a box. We have three regions in space; region I from ## \ - \infty, -L/2 ##, region II from ## \ -L/2, L/2 ##, and region III from ## \ L/2, \infty ##. For the...
  2. D

    I Shankar Quantum Mechanics, Chapter 5, Page 160-161

    For the case of general potential V(x), what does it mean when he says that there are always one more constraint than free parameters? At each interval, ψ and ψ' must be continuous, so that is 2 constraints at each interval, and I understand that there are 2 parameters of the wavefunction in...
  3. N

    Separating a wave function into radial and azimuthal parts

    I know how to work through this problem but I have a question on the initial separation of the wave function. Assuming ##\psi(\rho, \phi) = R(\rho)\Phi(\phi)## then for the azimuthal part of the wavefunction we have ##\Phi(\phi)=B\left(\frac \rho\Delta cos\phi+sin\phi\right)##, but this function...
  4. abrogard

    B Shankar on Lorentz Transformation: Does x' = ct'?

    On the Yale University Prof Shankar Youtube vid 'Lorentz Transformation' Prof Shankar writes up on the board that x = ct and then x prime = c t prime. It is the basis of all that follows. But i don't understand. at x = 0, t = 0 and x prime = 0 and t prime = 0. He's got that written up...
  5. J

    Question about an Eqn. in Shankar - wave function probability

    I don't see why it is not ##P(\omega)\propto |\langle \psi | \mathbb{P}_{\omega}|\psi\rangle |^2.## After all, the wavefunction ends up collapsing from ##|\psi\rangle## to ##\mathbb{P}_{\omega}|\psi\rangle.##
  6. AndreasC

    Quantum Where to Go Next: Quantum Mechanics Textbooks Beyond Shankar?

    In about a month or perhaps less I believe I will have finished my reading of Shankar. Which textbooks would you consider to be a next step from that? There are 3 things I would appreciate. One is slightly more mathematical rigour, perhaps something that makes greater use of methods from...
  7. Pushoam

    I Expanding a given vector into another orthonormal basis

    Equation 9.2.25 defines the inner product of two vectors in terms of their components in the same basis. In equation 9.2.32, the basis of ## |V \rangle## is not given. ## |1 \rangle ## and ## |2 \rangle ## themselves form basis vectors. Then how can one calculate ## \langle 1| V \rangle ## ? Do...
  8. Pushoam

    Show: Vectors e.g.(a,b,1) do not form vector space.

    Homework Statement Homework Equations definition of null vector, [/B] The Attempt at a Solution null vector : ## |0 \rangle = (0,0,0) ## inverse of (a,b,c) = ( - a, -b, -c) vector sum of the two vectors of the same form e.g. (c,d,1) + ( e,f,1) = ( c+e, d+f, 2) does not have the same...
  9. A

    Quantum QM Alternatives to Shankar for Undergraduate Level

    I am currently taking a second course on QM (at undergraduate level). The official texts of my course are Griffiths (we are covering the second half of it) and Shankar (for everything that is not in Griffiths). But after reading Shankar for a while, I found myself not really liking the book too...
  10. P

    Quantum Quantum Mechanics Textbook,Zettili vs Shankar

    Hello Everyone, I am an undergraduate physics student who planned to study quantum mechanics. I have been reading the introductory book by Griffiths, however I found that his book seldom uses Dirac Notation and there is little about mathematical formalism on quantum mechanics. Therefore I would...
  11. smodak

    Quantum Interesting new QFT book by Shankar

    https://www.amazon.com/dp/0521592100/?tag=pfamazon01-20 Yes, this is the same Shankar who wrote the QM book. It is not a pure QFT introduction like his QM book but seems more like QFT's application too Condensed matter.
  12. S

    Shankar Exercise 1.1.3 (Vector Spaces)

    <Mentor's note: moved from a technical forum, therefore no template.> I'm long out of college and trying to teach myself QM out of Shankar's. I'm trying to understand the reasoning here because I think that I am missing something... 1.1.3 1) Do functions that vanish at the endpoints x=0 and...
  13. abrogard

    What Does Shankar Mean in Prof Shankar's Introduction to Relativity?

    Hope this is a valid question. I can't quite understand this very simple thing. Prof Shankar's introduction to relativity on Youtube starting at about 50 minutes has a quick calculation that comes up with the Lorentz transform. I follow the maths, no problem. But he confuses me a bit when...
  14. R

    Quantum Is My Background Strong Enough for Shankar's Mechanics Book?

    I've taken Calc I to III and linear algebra, although the course was overall quite light. I don't know what legendre polynomials are, and haven't learned hamiltonians (and probably won't since its not in morin), When i start the book i will have finished david morins mechanics book,tenenbaums...
  15. Kostik

    Free particle propagator - Shankar POQM Eqn. 5.1.10, p. 153

    Can someone help with what must be a simple math issue that I'm stuck on. Shankar ("Principles of Quantum Mechanics" p. 153) evaluates the propagator for a free particle in Equation 5.1.10. A scan of the chapter is available here...
  16. Kostik

    Propagator for free particle: question about Shankar formula

    I am hung up on what must be a very elementary matter, but I’m unable to see where I’m wrong. I reference R. Shankar's "Principles of Quantum Mechanics". For the free particle with https://www.physicsforums.com/file:///C:/Users/DANIEL~1.ABR/AppData/Local/Temp/msohtmlclip1/01/clip_image002.png ...
  17. B

    MHB Shankar - Simultaneous Diagonalisation of Hermitian Matrices

    Asked to determine the eigenvalues and eigenvectors common to both of these matrices of \Omega=\begin{bmatrix}1 &0 &1 \\ 0& 0 &0 \\ 1& 0 & 1\end{bmatrix} and \Lambda=\begin{bmatrix}2 &1 &1 \\ 1& 0 &-1 \\ 1& -1 & 2\end{bmatrix} and then to verify under a unitary transformation that both can...
  18. B

    Shankar- Simultaneous Diagonalisation of Hermitian Matrices

    Folks, What is the idea or physical significance of simultaneous diagonalisation? I cannot think of anything other than playing a role in efficient computation algorithms? Thanks
  19. S

    Solving the Schödinger equation - R.Shankar's PQM, mistake?

    Hello! On p.145 of Shankar's Principles of Quantum Mechanics, the author derives the general propagator for the Schrodinger equation in the following manner. Shankar's working Expanding the state vector in the energy basis, |\psi(t)\rangle = \sum_{E} |E\rangle \langle E| \psi(t) \rangle...
  20. S

    Shankar, Feynman, Griffiths and Resnick?

    I know there are a lot of similar questions here but just hear me out. I am going to start self-studying quantum mechanics in a few days. I think I am going to use the MIT quantum mechanics 1 lectures as a starting point. But books will be essential as I spend most of my time in school. I have...
  21. H

    Passive Aggressive humor in Shankar

    Even though the text is largely quite serious, I sense a funny kind of humor in the way Shankar phrases a lot of things. Anyone else feel the same?
  22. P

    Quantum mechanics Shankar corrected version ?

    Hi I have just bought the hardback version of "Principles Of Quantum Mechanics" by Shankar online. The website stated that it is the corrected version from 2008 but the book has no mention of corrected version 2008 inside it. Does anyone know if the hardback version states inside the book that...
  23. Astrum

    Solving QM-like Problem (Shankar, Coupled Mass)

    This is solving a coupled mass problem using the techniques used in QM, it's in the mathematical introduction of Shankar. This equation was obtained by using the solution for ##x(t) = x_i(0)cos(\omega _i t)## and plugging it into ##\left| x(t) \right \rangle = \left| I \right \rangle x_i...
  24. N

    Non-canonical transformation, Shankar 2.8.5

    Homework Statement Suppose I release a particle at (x=a,y=0) with (p_x = b, p_y = 0) and you release one in the transformed state (x=0, y=a) with (p_x = b, p_y = 0) where the transformation is that we rotate the coordinates but not the momenta. This is a non canonical transformation that...
  25. Greg Bernhardt

    Quantum Principles of Quantum Mechanics by R. Shankar

    Author: R. Shankar Title: Principles of Quantum Mechanics Amazon Link: https://www.amazon.com/dp/0306447908/?tag=pfamazon01-20 Prerequisities: Contents:
  26. D

    Shankar Questions About Quantum Mechanics (Schwarz Inequality)

    Hello there, Im studying QM with Shankar's book. I'm wrestling myself trough the linear algebra now and I have some questiosn. Let me start with this one: I have absolutely no idea where this is coming from or what does it mean. I don't know how to multiply a ket with an inner...
  27. I

    Is it a bad idea to do quantum with Shankar without having Griffiths first?

    I have the option of doing either a one-semester QM course with Griffiths or a two-semester course with Shankar. Background is Eisberg and Resnick's "Quantum Physics". I really like quantum mechanics and would rather do two semesters, but will Shankar be too formal for an upper-level undergraduate?
  28. M

    Shankar, Ballentine or Zettili for a first book on QM?

    All three seem to be loved, mathematically rigorous, and appropriate as undergraduate-level texts. I have a good knowledge of classical physics, ODEs and PDEs, linear algebra and multivar calculus, but no knowledge of analytical mechanics or QM. Some opinions on these or other recommendations...
  29. J

    Shankar 14.4.1 using Ehrenfest's Theorem

    Homework Statement Show that if H = -\gamma\mathbf{L\cdot B}, and B is position independent, \frac{\mathrm{d} \left \langle \mathbf{L} \right \rangle}{\mathrm{d} t}=\left \langle \boldsymbol\mu \times\mathbf{B} \right \rangle=\left \langle \boldsymbol\mu \right \rangle\times\mathbf{B} Here H...
  30. W

    Question in Principles of Quantum Mechanics by Shankar

    Hi, Im studying a book "Principles of Quantum Mechanics" by Shankar. Im in the fifth chapter, Simple Problems in One dimension. In page 169 to 170, the book says about the standard procedure for finding the fate of the incident wave packet. But i don't understand why we are finding...
  31. B

    Comparing "The" vs. "A" Rotation Matrix in Shankar 12.4.4

    Shankar 12.4.4 - "the" rotation matrix vs. "a" rotation matrix (tensor operators QM) Homework Statement My question comes up in the context of Shankar 12.4.4. See attached .pdf. Homework Equations See attached .pdf The Attempt at a Solution See attached .pdf I have this...
  32. Q

    Solving Shankar Problem 14.4.3

    Hi everyone, I am really stuck here, and I would really appreciate if someone could help me out. The statement of the problem is attached as a image. Some equations referred by the problem are also attached in another image. I will try to explain how I have reasoned using more words than...
  33. T

    Finding eigenvalues, Shankar exercise 1.8.3

    First, I appologise if this is in the wrong place, while the book is QM, the question is pure maths. Also I'm not sure if this techically counts as homework as I am self studying. Finally, sorry for the poor formatting, I'm not that good with LaTeX Homework Statement Given the matrix...
  34. G

    Quantum Mechanics: Shankar or Cohen-Tannoudji?

    Has anybody read/use both these books? Which one is "better"? Thanks.
  35. maverick_starstrider

    Quantum Books: Ballentine or Shankar?

    Hi, I have a pretty strong background in quantum and I've already gone through sakurai using shankar as a reference for courses and such. However, this summer, I want to go through a comprehensive quantum book cover to cover in preparation for going through Zee's QFT book. Which do people...
  36. L

    Shankar CH1 Derivative of Dirac delta

    Hi, On p67 of shankar Principles of QM, he considers the delta functions derivative. He says: \int \delta'(x-x')f(x')dx'= \int \frac{d\delta(x-x')}{dx}f(x')dx'= \frac{d}{dx}\int \delta(x-x') f(x')dx'=\frac{df(x)}{dx} I don't understand how the second equality follows, how can the...
  37. J

    Disproving Shankar's PQM Equations: Example 1.8.6 | Farside Physics

    shankar "PQM" is wrong? Shankar Principles of Quantum mechanics Pag 46: Example 1.8.6 The movement equations are in my opinion wrong. Consider the following link for the same equations http://farside.ph.utexas.edu/teaching/315/Waves/node17.html
  38. D

    Normalized state vector for bosons, Shankar problem

    Homework Statement Two identical bosons are found to be in states |\phi> and |\psi>. Write down the normalized state vector describing the system when <\phi|\psi>\neq0.Homework Equations The normalized state vector for two bosons with <\phi|\psi>=0, using the fact that...
  39. D

    Shankar One-Dimensional Problem

    Homework Statement Exercise 5.2.2 (b.) Prove the following theorem: Every attractive potential in one dimension has at least one bound state. Hint: Since V is attractive, if we define V(\infty)=0, it follows that V(x)=-|V(x)| for all x. To show that there exists a bound state with E<0...
  40. Q

    Compare the following books - Griffiths, Sakurai, Shankar

    Ok, maybe the subject has been discussed in some manner in other posts, but I would like a clear comparison between : * David J Griffiths - Introduction to Quantum Mechanics * Shankar - Principles of Quantum Mechanics * Sakurai - Modern Quantum Mechanics What is your experience with these...
  41. Q

    Quantum Mechanics: Shankar vs Sakurai

    I've started to learn Quantum Mechanics from Shankar's book "Principles of Quantum Mechanics". My qm professor recommended Sakurai to me, but I feel more comfortable using Shankar. What can you tell me about these 2 books? Which one do you prefer?
  42. J

    QM: Angular Momentum-Wavefunction "psi" & Schrodinger's Eq.

    Homework Statement Particle described by wavefunction psi(r,theta,phi) = A*Exp[-r/a0] (a0 = constant) (1) What is the angular momentum content of the state (2) Assuming psi is an eigenstate in a potential that vanishes as r -> infinity, find E (match leading terms in Schrodinger's...
  43. E

    Shankar Exercise 2.5.1 - Hamiltonion

    Homework Statement Could someone get me started with Exercise 2.5.1 in Shankar's Principles of Quantum Mechanics? Does this forum support TeX or LaTeX? Homework Equations The Attempt at a Solution
  44. S

    Shankar vs Griffiths: A Comparison of Quantum Mechanics Textbooks

    What are your opinions on Shankar: Principles of Quantum Mechanics and Griffiths: Introduction to Elementary Particle physics? I've decided to use them to study my two QM modules and my Particle Physics Modules, instead of the recommended texts. So how good are they?
  45. R

    Shankar Page 153: 5.1.10 & 5.1.11 Meaning - Delta Function?

    Would someone mind opening his or her Shankar page 153 and tell me what (5.1.10) and (5.1.11) exactly mean? Does (5.1.10) stand for a delta function? thank you
  46. L

    Principles of QM - R. Shankar: Good Start ?

    Hi, Have to get my Christmas wish lists together and was looking for a good book to buy on QM. I need some background on the mathematics involved. I'm also self-studying, with the help of you all of course :) I found this book to meed my needs, but I'm a bit unsure to spend a lot of...
  47. G

    QM scattering - Section 19.5 in Shankar

    The question is: 19.5.4 Show that the s-wave phase shift for a square well of depth V0 and range r0 is δ0 = -k r0 + tan-1{(k/k') tan(k'r0)} where k' and k are the wave numbers inside and outside the well. For k small, kr0 is some small number and we ignore it. Let us see what happens...