Proof that Gauss- Seidel iteration method converges for any initial x if the matrix is self-adjoint and...











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I am trying to create a direct proof that if the matrix A is self-adjoint and positive-definite, then the Gauss-Seidel iteration converges for any initial ${bf x}_{0}$



I think I need to prove $rho({bf T}) < 1$ so
I begin by letting my ${bf A} = {bf D} - {bf L} - {bf L}^*$ and ${bf T}_{G}= ({bf D}-{bf L})^{-1}{bf L}^*$ where



I can use the fact that I can multiply ${bf D}^{1/2}$ to both sides of ${bf T}_{G}$ since Eigenvalues are insensitive giving me the following:



${bf T}_1 = {bf D}^{1/2}{bf T}_{G}{bf D}^{-1/2} = ({bf I} -
{bf L}_{1})^{-1}{bf L}_{1}^*$
, where ${bf L}_{1} =
{bf D}^{-1/2}{bf L}{bf D}^{-1/2}$
.



I'm stuck as to what to do next. Any help is appreciated!










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  • 1




    Check, e.g., Theorem 4.5 here
    – Algebraic Pavel
    Nov 29 at 9:59















up vote
0
down vote

favorite












I am trying to create a direct proof that if the matrix A is self-adjoint and positive-definite, then the Gauss-Seidel iteration converges for any initial ${bf x}_{0}$



I think I need to prove $rho({bf T}) < 1$ so
I begin by letting my ${bf A} = {bf D} - {bf L} - {bf L}^*$ and ${bf T}_{G}= ({bf D}-{bf L})^{-1}{bf L}^*$ where



I can use the fact that I can multiply ${bf D}^{1/2}$ to both sides of ${bf T}_{G}$ since Eigenvalues are insensitive giving me the following:



${bf T}_1 = {bf D}^{1/2}{bf T}_{G}{bf D}^{-1/2} = ({bf I} -
{bf L}_{1})^{-1}{bf L}_{1}^*$
, where ${bf L}_{1} =
{bf D}^{-1/2}{bf L}{bf D}^{-1/2}$
.



I'm stuck as to what to do next. Any help is appreciated!










share|cite|improve this question




















  • 1




    Check, e.g., Theorem 4.5 here
    – Algebraic Pavel
    Nov 29 at 9:59













up vote
0
down vote

favorite









up vote
0
down vote

favorite











I am trying to create a direct proof that if the matrix A is self-adjoint and positive-definite, then the Gauss-Seidel iteration converges for any initial ${bf x}_{0}$



I think I need to prove $rho({bf T}) < 1$ so
I begin by letting my ${bf A} = {bf D} - {bf L} - {bf L}^*$ and ${bf T}_{G}= ({bf D}-{bf L})^{-1}{bf L}^*$ where



I can use the fact that I can multiply ${bf D}^{1/2}$ to both sides of ${bf T}_{G}$ since Eigenvalues are insensitive giving me the following:



${bf T}_1 = {bf D}^{1/2}{bf T}_{G}{bf D}^{-1/2} = ({bf I} -
{bf L}_{1})^{-1}{bf L}_{1}^*$
, where ${bf L}_{1} =
{bf D}^{-1/2}{bf L}{bf D}^{-1/2}$
.



I'm stuck as to what to do next. Any help is appreciated!










share|cite|improve this question















I am trying to create a direct proof that if the matrix A is self-adjoint and positive-definite, then the Gauss-Seidel iteration converges for any initial ${bf x}_{0}$



I think I need to prove $rho({bf T}) < 1$ so
I begin by letting my ${bf A} = {bf D} - {bf L} - {bf L}^*$ and ${bf T}_{G}= ({bf D}-{bf L})^{-1}{bf L}^*$ where



I can use the fact that I can multiply ${bf D}^{1/2}$ to both sides of ${bf T}_{G}$ since Eigenvalues are insensitive giving me the following:



${bf T}_1 = {bf D}^{1/2}{bf T}_{G}{bf D}^{-1/2} = ({bf I} -
{bf L}_{1})^{-1}{bf L}_{1}^*$
, where ${bf L}_{1} =
{bf D}^{-1/2}{bf L}{bf D}^{-1/2}$
.



I'm stuck as to what to do next. Any help is appreciated!







linear-algebra numerical-methods numerical-linear-algebra positive-definite






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edited Nov 30 at 3:44

























asked Nov 29 at 4:38









Jennifer Laundey

84




84








  • 1




    Check, e.g., Theorem 4.5 here
    – Algebraic Pavel
    Nov 29 at 9:59














  • 1




    Check, e.g., Theorem 4.5 here
    – Algebraic Pavel
    Nov 29 at 9:59








1




1




Check, e.g., Theorem 4.5 here
– Algebraic Pavel
Nov 29 at 9:59




Check, e.g., Theorem 4.5 here
– Algebraic Pavel
Nov 29 at 9:59















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