Recent content by anuttarasammyak

  1. anuttarasammyak

    J_1(x) = (x^2/10)*(J_1(x) + J_3(x)) How to solve?

    This anti-symmetric equation has six non-zero solutions.
  2. anuttarasammyak

    Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?

    Thank you @Demystifier 1. I observe that a. ## \bar{g}_{\mu\nu}-g_{\mu\nu}## transforms as a covariant tensor under coordinate transformation b. ## \bar{g}^{\mu\nu}-g^{\mu\nu}## transforms as a contravariant tensor under coordinate transformation. c. There exists a tensor whose covariant...
  3. anuttarasammyak

    Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?

    I should appreciate it if you could teach me how to verify it.
  4. anuttarasammyak

    Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?

    Thank you, @Demystifier. In general, the difference of two tensors is again a tensor. However, in the context of variations of the metric tensor, the quantities $$ \bar{g}_{\mu\nu}-g_{\mu\nu}$$ $$ \bar{g}^{\mu\nu}-g^{\mu\nu}$$ do not transform as tensors. I have verified this.
  5. anuttarasammyak

    J_1(x) = (x^2/10)*(J_1(x) + J_3(x)) How to solve?

    You forgot to put double dollar signs at head and tail of the equalion lines. I put them. ------------ Has any one any idea to solve this equation ##J[1, x] = (x^2/10)*(J[1, x] + J[3, x])##, in which J are spherical Bessel function normally write as ##j_1 (x)## and ##j_3(x)## Methods 1 serial...
  6. anuttarasammyak

    Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?

    It is a tensor whose covariant and contravariant components are ##\delta g_{\mu\nu}## and ##-\delta g^{\mu\nu}##, respectively. Returning to the original question, does there exist such a quantity whose covariant and contravariant components are ##\delta g_{\mu\nu}## and ##\delta g^{\mu\nu}## ...
  7. anuttarasammyak

    Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?

    1. We can derive the equation $$ \delta g^{\mu\nu}=-g^{\mu\alpha}g^{\nu\beta}\delta g_{\alpha\beta} $$ by indeces up down operation. In the world whose metric tensor is g, $$ g^{\mu\nu}=g^{\mu\alpha}g^{\nu\beta}g_{\alpha\beta} $$ In another new world whose metric tensor is ##\bar{g}##, $$...
  8. anuttarasammyak

    Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?

    Now I know that $$ (\delta g)^{\mu\nu}=g^{\mu\alpha}g^{\nu\beta}(\delta g)_{\alpha\beta} $$ $$ \delta g^{\mu\nu}=-g^{\mu\alpha}g^{\nu\beta}\delta g_{\alpha\beta} $$ Here I have a question. Is $$(\delta g)_{\alpha\beta}=\delta g_{\alpha\beta}$$ $$(\delta g)^{\alpha\beta}=-\delta...
  9. anuttarasammyak

    Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?

    @PAllen @Demystifier Thanks. I went a bit easy on T .
  10. anuttarasammyak

    Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?

    To put it simply $$ \bar{\delta g}=-\delta \bar{g} $$ May I understand that ##\{\delta g, \bar{\delta g}\}=\{\delta g, -\delta \bar{g} \}## are tensor indeces up-down pair but ##\{\delta g, \delta \bar{g}\}## are not that pair which does not follow ordinary indeces up-down transformation but...
  11. anuttarasammyak

    Undergrad Matrix representation of rank-2 spinors

    I have read the matrix representation in Landau and Lifshitz.
  12. anuttarasammyak

    High School Confusion about one of Maxwell's equations

    Yes. No charge, no current.
  13. anuttarasammyak

    High School Confusion about one of Maxwell's equations

    Yes, loop integral of electric field is generated with no regard to the wire. Free electrons in the conductor wire on the loop are required for generation of the force which are charge times electric field.
  14. anuttarasammyak

    Undergrad Mixed approximation vs. full approximation for a power series expansion

    We are sharing the situation. I do not find any essential difference in the drawings.