Basis Definition and 1000 Threads

  1. B

    Derivative of transformation of basis in R^n

    I've just studied the implicit function theorem and if we assume the theorem is true then we can easily compute the following: id_n = D(id_n)_x = D({f^-1}°{f})_x = {D(f^-1)_f(x)} ° {Df_x} where D(*)_a means the derivative of * at x. OKay... so this was very straightforward until I began...
  2. R

    MHB Find polynomials in S, then find basis for ideal (S)

    Hi There, I posted this question over at MHF to no avail, I'm not really sure what the ruling is on this kind of thing, I know this site was setup when MHF was down for a long time but you seem to still be active and a lot of clever people are still here so hopefully you don't mind taking a...
  3. D

    Find if 3 vectors form a basis in space R^4

    Homework Statement Is the system of vectors a1=(1,-1,0,1), a2=(2,3,-1,0), a3=(4,1,-1,4) linearly independent? Do these vectors form a basis in the vector space R^4? State why. Homework Equations The Attempt at a Solution I have done the first part of the exercise. I have found...
  4. M

    Basis, Linear Transformation, and Powers of a Matrix

    Homework Statement Let A be an 3x3 matrix so that A^3 = {3x3 zero matrix}. Assume there is a vector v with [A^2][v] ≠ {zero vector}. (a) Prove that B = {v; Av; [A^2]v} is a basis. (b) Let T be the linear transformation represented by A in the stan- dard basis. What is [T]B? Homework...
  5. V

    Capturing n basis vectors by single one

    Normally, you need how system transforms n basis vectors to say how it transforms arbitrary vector. For instance, when your signal is presented in Fourier basis, you need to know how system responds to every sine. But, I have noted that it is not true for the simplest standard basis. You just...
  6. B

    Basis vectors and abstract index notation

    First of all, I'd like to say hi to all the peole here on the forum! Now to my question: When reading some general relativity articles, I came upon this strange notation: T^{a}_{b} = C(dt)^{a}(∂_{t})_{b} + D(∂_{t})^{a}(dt)_{b}. Can someone please explain to me what this means? Clearly...
  7. K

    About basis of the honeycomb lattice

    Hi there, I am reading the book "Condensed Matter Physics" second edition by Michael P. Marder. It stated in page 9 that one basis of the the honeycomb lattice is \vec{v}_1 = a [0 \ 1/(2\sqrt{3})], \qquad \vec{v}_2 = a [0 \ -1/(2\sqrt{3})] which is based on figure 1.5(B) in page...
  8. K

    Finding a basis for the following vectors.

    Find a basis and the dimension for the subspace of R^3(3D) spanned by the vectors {(0,1,-2),(3,0,1),(3,2,-3)} The dimension is 2 regardless if i put the vectors in row space or column space form. But to find the basis I need to put it in row space form. Can anyone please explain when I...
  9. K

    Finding the basis for a set of vectors.

    The set is (1,3),(-1,2),(7,6) it is in R2 so I don't get why there are 3 elements. I assumed they are not vectors but points instead. but if they are points then it becomes a line, and the answer is that its dimension is 2, and a basis is (1,0) and (0,1) Could someone explain this? Thanks
  10. S

    Basis of kernel and image of a linear transformation. (All worked out)

    http://dl.dropbox.com/u/33103477/linear%20transformations.png My solution(Ignore part (a), this part (b) only) http://dl.dropbox.com/u/33103477/1.jpg http://dl.dropbox.com/u/33103477/2.jpg So I have worked out the basis and for the kernel of L1 and image of L2, so I have U1 and U2...
  11. S

    Procedure for orking out the basis of the kernel of a linear transformation.

    I am working on a problem dealing with transformations of a vector and finding the basis of its kernel. Now I have worked out everything below but after reading the definitions I am a bit confused, hence just want verification if the procedure I am following is correct. My transformed matrix is...
  12. S

    Basis of linear transformations

    http://dl.dropbox.com/u/33103477/linear%20transformations.png My attempt was to first find the transformed matrices L1 and L2. L1= ---[3 1 2 -1] -------[2 4 1 -1] L2= ---[1 -1] -------[1 -3] -------[2 -8] -------[3 -27] Now reducing L1, I have -------[1 0 7/10 -3/10]...
  13. S

    A one-form versus a dual basis vector

    Hi everyone, Pardon the neophyte question, but is a one-form the same thing as a dual basis vector? If not, are they related in some way, or completely different concepts/entities? Thank you!
  14. A

    How to find the orthogonal basis?

    Can somebody help me how to approach this problem.I am having trouble finding the orthogonal basis.
  15. E

    Taking vectors from one basis to another [Byron and Fuller]

    B&F have the following: \delta_{i j} = e'_i \cdot e'_j = a_{i k} \left( e_k \cdot e'_j \right) = a_{i k} a_{j k} and they ask the reader to show that a_{k i} a_{k j} = \delta_{i j} Does it suffice to show the following? : \delta_{i j} = a_{i k} a_{j k} \to \delta_{j i} = \left(...
  16. S

    Difficult theoretical problem on basis vectors

    How the hell do you prove that the components of a vector w.r.t. a given basis are unique? I have literally no idea how to begin! It's just that with these theoretical problems there's no straightforward starting point!
  17. V

    Need for Separate Basis for Kernel: Explained by Hello

    hello :) I was trying to prove the following result : for a linear mapping L: V --> W dimension of a domain V = dimension of I am (L) + dimension of kernel (L) So, my doubt actually is that do we really need a separate basis for the kernel ? Theoretically, the kernel is a subspace of the...
  18. T

    What is the basis for W perp in the Gram Schmidt process?

    Homework Statement Let W be a subspace of ℝ4 spanned by the vectors: u1 = [1; -4; 0; 1], u2 = [7; -7; -4; 1] Find an orthogonal basis for W by performing the Gram Schmidt proces to there vectors. Find a basis for W perp (W with the upside down T). Homework Equations Gram...
  19. R

    Basis functions of a differential equation, given boundary conditions

    First off, I've never taken a differential equations class. This is for my Math Methods for Physicists class, and we are on the topic of DE. Unfortunately, we didn't cover this much, so most of what I am about to show you comes from the professor giving me tips and my own common sense. I'd...
  20. F

    Linear transformation with standard basis

    Homework Statement Let s be the linear transformation s: P2→ R^3 ( P2 is polynomial of degree 2 or less) a+bx→(a,b,a+b) find the matrix of s and the matrix of tos with respect to the standard basis for the domain P2 and the standard basis for the codomain R^3 The Attempt at a...
  21. B

    How Does the Preferred Basis Problem Impact Quantum State Representation?

    Homework Statement I'm trying to understand the preferred basis problem in the foundations of QM Ok so I read somewhere that in general any state can be decomposed in different ways. I don't quite see how this is meant to work Suppose 'up' / 'down' represent z component of ang mom...
  22. S

    Finding a basis given part of that basis

    Homework Statement This is the question on my assignment: In each case below, given a vector space V , find a basis B for V containing the linearly independent set S ⊂ B. It has a bunch of different cases but I think that if you help me with the following two, I will learn enough to do...
  23. T

    Is Change of Basis the Solution to My Linear Algebra Problem?

    Homework Statement The Attempt at a Solution So first I thought to myself that the proper way of doing this problem was to construct each of the standard basis vectors as a linear combination of the basis given us. I have, T(1,0,0) = \frac{1}{2} T(1,0,1) + \frac{1}{2} T(1,0,-1) =...
  24. F

    Jordan Basis for Differential Operator

    Homework Statement Let V = P_n(\textbf{F}) . Prove the differential operator D is nilpotent and find a Jordan basis. Homework Equations D(Ʃ a_k x^k ) = Ʃ k* a_k * x^{k-1} The Attempt at a Solution I already did the proof of D being nilpotent, which was easy. But we haven't covered...
  25. F

    Gram-Schmidt Method for orthogonal basis

    I have S= {(1,1,0,1) (1,0,-1,0) (1,1,0,2)} its one of the subset and second it T= {(x,y,z,2x-y+3z)} If you were to use Gram-Schmidt method to find the orthogoan basis for T who would you processed? I really don't understand this concept. I know from T , the hyperplane is 2x-y+3z so the...
  26. M

    Reduced Grobner basis form a regular sequence?

    Does anyone know if a set of homogeneous polynomials forms a reduced Grobner basis, then they form a regular sequence in the polynomial ring? Any references? All the references that I have looked at (so far) have not related the two. If this is not true, can you give me a counterexample...
  27. M

    Can an electron move to a higher energy level on a permanent basis?

    Hi, I have some very basic questions regarding electron energy levels/states. In the basic atom model when an electron becomes excited (i.e. absorbs a photon or collides with a nearby atom or particle) and moves into an energy state greater than its ground state, must it always eventually...
  28. T

    Orthogonal Basis and Inner Products

    Homework Statement The Attempt at a SolutionSince A is a vector in V and since the A_i form a basis, we can write A as a linear combination of the A_i. We write A = x_1 A_1 + ... + x_n A_n. Thus, we have, <x_1 A_1 + ... + x_n A_n,A_i> = 0 = x_1 <A_1,A_i> + ... + x_n <A_n,A_i>. Because...
  29. F

    Crystals: difference between basis and unit cell

    Hello Forum, a lattice is a set of points. We can place a basis at each set of points. The basis can be one atom or a group of atoms. I thought that a translation of the basis would produce the whole crystal... How is a basis different from the unit cell? Are they the same thing...
  30. A

    Trouble understanding MTW particulary noncoordinate basis

    Background:(you might not be interested so you can skip if you want) I am trying to learn general relativity using the Book Gravitation by Misner, Thorn and Wheeler. The book for the most part seems easy for me to understand but once in a while words i neither heared nor can find the meaning of...
  31. F

    Density matrix elements, momentum basis, second quantization

    Hello everyone, I'm having some trouble, that I was hoping someone here could assist me with. I do hope that I have started the topic in an appropriate subforum - please redirect me otherwise. Specifically, I'm having a hard time understanding the matrix elements of the density matrix...
  32. D

    RElation of partial differential operator and Basis vector

    Hi everyone: How is the following derived? Just for example: \Deltax\alphae\alpha=\Deltax\alpha(\delta/\deltax\alpha) does it not mean? e\alpha=\delta/\deltax\alpha But How?
  33. F

    Calculate the discriminant of a basis [Number Theory]

    Question: The needed proposition and two examples: This is as far as I have got: I need to reduce this (I think) so I can represent is as a matrix! Any idea on how to do this? Thanks
  34. matqkks

    Change Basis: Reasons to Write Vector in Rn Other Than Standard Basis

    Why should we want to write a vector in Rn in other than standard basis? A normal application of linear transformations in most textbooks is converting a given vector in standard basis to another basis. This is sometimes a tedious task. Why carry out this task? Thanks for your replies in advance.
  35. G

    Finding Basis of Null Space and Range

    Homework Statement Prove T is a linear transformation and find bases for both N(T) and R(T). Homework Equations The Attempt at a Solution T:M2x3(F) \rightarrow M2x2(F) defined by: T(a11 a12 a13) (a21 a22 a23) (this is one matrix) = (2a11-a12 a13+2a12)...
  36. F

    The General Linear Group as a basis for all nxn matrices

    I'm trying to prove that every nxn matrix can be written as a linear combination of matrices in GL(n,F). I know all matrices in GL(n,F) are invertible and hence have linearly independent columns and rows. I was thinking perhaps there is something about the joint bases for the n-dimensional...
  37. S

    Expectation values of QHO in |n> basis

    Is it possible to express ANY observable A(X,P) in terms of the ladder operators? I know how to evaluate expectation values in the |n> basis given the operators in terms of a & a+, but was trying to figure out <1/X^2>. How do you express 1/X^2 in terms of ladder operators? <ψ|(1/X^2)|ψ> can be...
  38. T

    Dimension of Vector Space R^X: Finite/Infinite Cases

    The finite case is fine, as a vector space it is easy to show that R^X is isomorphic to R^n. What about when X is infinite? I believe it is true in general that dim(R^X) = #(X), which I hope holds in the infinite case too. I know that the set given by B={b_x; x in X} defined as b_x(y) =...
  39. M

    Density of State for a two atom basis

    Homework Statement I have a problem on my assignment in which I am required to find the specific heat of a two atom basis (diatomic) using the Debye model. My problem is coming up with the density of states for a diatomic setup in 1D. Homework Equations Density of state...
  40. C

    Video Games and Their Basis in Theory

    Are there any theories with which the mass effect fields of Mass Effect and the slipstream space of Halo draw inspiration from? Is there any scientific basis for either, or is it complete fantasy?
  41. K

    Question regarding basis of function space

    I only possesses a rudimentary understanding of Linear Algebra so I'm not going to be rigorous in my explanation, but is the concept of an infinite basis well defined? More specifically, I was thinking about how the polynomials could form a basis for function space, given that every function has...
  42. A

    Sobolev type norms and basis functions

    Hello everybody, I am given a "Sobolev type innerproduct" \langle f,g \rangle_{\alpha} = \langle f,g \rangle_{L^2} + \alpha \langle Rf,Rg \rangle_{L^2} for some \alpha \geq 0 and R some differential operator (e.g. the second-derivative operator). My question is now whether a function...
  43. S

    How to Find the B Matrix in Matlab for Wavelet Basis Functions?

    Hi all, Say that I have a 1D signal such that f=Bw where f is the signal B is the basis functions and w is the wave co-efficients. The question that I have is how do I find the B matrix in Matlab. I am looking through WaveLab and Rice Wavelet packages but simply cannot find an answer. As...
  44. P

    Do Columns of M² Form a Basis?

    Hi everyone, This not a homework question. I'm reviewing some linear algebra and I found this on a worksheet. I just need a hint on how to approach this problem. Let β=\{ v_1,v_2,...,v_n\} be a basis for R^n . Let M be the matrix whose columns are the basis vectors in β. Do the...
  45. S

    What is the basis for a vector space in Structural Engineering?

    I'm currently doing a self study course on Linear Algebra. Can anyone give me an example of vector space and basis with reference to Structural Engineering? For example I have a displacement vector for a simply supported beam as: [thata_a theta_b]^T where; theta_a and theta_b...
  46. S

    What is the basis for the theory that WIMPs could be detected by

    What is the basis for the theory that WIMPs could be detected by seeing a vibration in the atomic nucleus of normal matter? If they (all) really do interact so weakly, why do scientist think they might be able to detect just a few?? an explanation in layman's terms would be great. thanks?
  47. S

    Finding basis functions for approximating transcendental function

    I am working on a problem where I want to approximate a transcendental function of the form f(x) = x^Ne^{x} for x \geq 0 as a linear combination of functions of the form x^v \text{where} -1 < v < 0. How can I find the basis functions of the desired form to represent my transcendental...
  48. B

    What is the Basis of a Quotient Ring?

    In my Abstract Algebra course, it was said that if E := \frac{\mathbb{Z}_{3}[X]}{(X^2 + X + 2)}. The basis of E over \mathbb{Z}_{3} is equal to [1,\bar{X}]. But this, honestly, doesn't really make sense to me. Why should \bar{X} be in the basis without it containing any other \bar{X}^n...
  49. A

    How do change of basis matrices work in linear algebra?

    Given a basis A = {a1,a2...an} we can always translate coordinates originally expressed with this basis to another basis A' = {a1',a2'...an'}. To do this we simply do some matrix-multiplication and it turns out that the change of basis matrix equals a square matrix whose rows are the coordinates...
  50. L

    Change of basis matrix(linear algebra)

    Hi I'm stuck on this problem and I could not find similar examples anywhere.. any help would be greatly appreciated, thank you. Homework Statement Compute the change of basis matrix that takes the basis V1 = \begin{bmatrix} -1 \\ 3 \end{bmatrix} V2 = \begin{bmatrix} 2 \\ 5 \end{bmatrix}...
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