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May
7
revised Preconditioning and effects on precision of solution of LSE
corrected reference
May
7
comment Preconditioning and effects on precision of solution of LSE
I do not think that your answer makes sense. Preconditioning precisely means decreasing the condition number. So there is no 'balancing' necessary between error magnification and convergence rates. In particular, my question regards only the numerical level - it is about the stability of numerical algorithms.
May
3
asked Preconditioning and effects on precision of solution of LSE
Apr
5
comment Boundedness of a Solution Operator
@user17904: You need to show that for Sobolev space $H$ of sufficient regularity the trace from $H$ to $L^2(\partial\Omega)$ has closed range. Than a bounded right-inverse exists by functional analysis. Typically, you can prove surjectivity, say, by partition of unity, smoothing and an explicit construction.
Mar
20
revised fundamental theorem of linear inequalities
added 336 characters in body
Mar
7
comment pseudoinverse under change of norm
I have completely rewritten the question.
Mar
7
revised pseudoinverse under change of norm
complete rewrite
Mar
7
accepted What can be said about the minimizer of $\| b - A x \| ^2+ \| x \|^2$?
Mar
7
asked pseudoinverse under change of norm
Mar
7
asked What can be said about the minimizer of $\| b - A x \| ^2+ \| x \|^2$?
Mar
6
asked Mappings preserving convex polyhedra
Mar
4
comment An variation of “Lk” in simplicial complexes
@StefanH.: Yes, thanks.
Mar
4
revised An variation of “Lk” in simplicial complexes
edited body
Mar
4
asked An variation of “Lk” in simplicial complexes
Feb
23
awarded  Popular Question
Feb
13
comment How can not-equals be expressed as an inequality for a linear programming model
It is intutive it does not work, because polyhedrons are convex and closed, while not-equals correspond to non-convex open regions.
Feb
13
asked fundamental theorem of linear inequalities
Feb
1
accepted Expansion of $x^{-1/2}$ at $0$
Feb
1
revised Expansion of $x^{-1/2}$ at $0$
clarification
Feb
1
asked Expansion of $x^{-1/2}$ at $0$