Integral form of the conservation law $u_t+f(u)_x=0$ The 2019 Stack Overflow Developer Survey Results Are In Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Prove an identity for the continuous integral solution of the conservation lawreversibility scalar conservation lawEntropy solution to scalar conservation lawEvans PDE Conservation Law IntegralWeak solutions of initial value problem of conservation laws with $L^infty$ initial dataNonsmooth data in the conservation laws, their approximations and limitsProperties of the solution of conservation lawsFinite-difference vs finite-volume schemes for conservation lawsNumerical convergence of Godunov schemeDiscrete entropy inequality for hyperbolic system

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Integral form of the conservation law $u_t+f(u)_x=0$



The 2019 Stack Overflow Developer Survey Results Are In
Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Prove an identity for the continuous integral solution of the conservation lawreversibility scalar conservation lawEntropy solution to scalar conservation lawEvans PDE Conservation Law IntegralWeak solutions of initial value problem of conservation laws with $L^infty$ initial dataNonsmooth data in the conservation laws, their approximations and limitsProperties of the solution of conservation lawsFinite-difference vs finite-volume schemes for conservation lawsNumerical convergence of Godunov schemeDiscrete entropy inequality for hyperbolic system










0












$begingroup$


Consider the conservation law given by
$$u_t+f(u)_x=0$$
We know that in general weak solutions are not smooth but are bounded in $L^infty$ norm (they do not belong to Sobolev spaces).



However while deriving the numerical schemes most of the books say, integrating the conservation law over $(a,b) times (t_1,t_2)$ and applying fundamental theorem of calculus we get
$$int_a^b u(x,t_1)dx - int_a^b u(x,t_2)dx= -int_t_1^t_2 f(u(b,t)dt+ int_t_1^t_2 f(u(a,t)dt$$
I have the following doubts:



  1. How can we perform integration by parts as the solution does not possess any regularity?


  2. If a function satisfies the above integral formulation, can we say that it is a weak solution? Conversely, if $u$ is a weak solution, will it satisfy the above integral formulation?


Thank you.










share|cite|improve this question











$endgroup$
















    0












    $begingroup$


    Consider the conservation law given by
    $$u_t+f(u)_x=0$$
    We know that in general weak solutions are not smooth but are bounded in $L^infty$ norm (they do not belong to Sobolev spaces).



    However while deriving the numerical schemes most of the books say, integrating the conservation law over $(a,b) times (t_1,t_2)$ and applying fundamental theorem of calculus we get
    $$int_a^b u(x,t_1)dx - int_a^b u(x,t_2)dx= -int_t_1^t_2 f(u(b,t)dt+ int_t_1^t_2 f(u(a,t)dt$$
    I have the following doubts:



    1. How can we perform integration by parts as the solution does not possess any regularity?


    2. If a function satisfies the above integral formulation, can we say that it is a weak solution? Conversely, if $u$ is a weak solution, will it satisfy the above integral formulation?


    Thank you.










    share|cite|improve this question











    $endgroup$














      0












      0








      0


      1



      $begingroup$


      Consider the conservation law given by
      $$u_t+f(u)_x=0$$
      We know that in general weak solutions are not smooth but are bounded in $L^infty$ norm (they do not belong to Sobolev spaces).



      However while deriving the numerical schemes most of the books say, integrating the conservation law over $(a,b) times (t_1,t_2)$ and applying fundamental theorem of calculus we get
      $$int_a^b u(x,t_1)dx - int_a^b u(x,t_2)dx= -int_t_1^t_2 f(u(b,t)dt+ int_t_1^t_2 f(u(a,t)dt$$
      I have the following doubts:



      1. How can we perform integration by parts as the solution does not possess any regularity?


      2. If a function satisfies the above integral formulation, can we say that it is a weak solution? Conversely, if $u$ is a weak solution, will it satisfy the above integral formulation?


      Thank you.










      share|cite|improve this question











      $endgroup$




      Consider the conservation law given by
      $$u_t+f(u)_x=0$$
      We know that in general weak solutions are not smooth but are bounded in $L^infty$ norm (they do not belong to Sobolev spaces).



      However while deriving the numerical schemes most of the books say, integrating the conservation law over $(a,b) times (t_1,t_2)$ and applying fundamental theorem of calculus we get
      $$int_a^b u(x,t_1)dx - int_a^b u(x,t_2)dx= -int_t_1^t_2 f(u(b,t)dt+ int_t_1^t_2 f(u(a,t)dt$$
      I have the following doubts:



      1. How can we perform integration by parts as the solution does not possess any regularity?


      2. If a function satisfies the above integral formulation, can we say that it is a weak solution? Conversely, if $u$ is a weak solution, will it satisfy the above integral formulation?


      Thank you.







      analysis pde numerical-methods hyperbolic-equations






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Apr 8 at 13:43









      Andrews

      1,2962423




      1,2962423










      asked Apr 4 at 12:39









      RosyRosy

      1476




      1476




















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