- #1
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Can a measurable function be a.e. equal to a non-measurable function?
Let ##(X,\Sigma,\mu)## be an arbitrary measure space. Let M be the set of measurable functions from X into ##\mathbb C##. I know that M is closed under pointwise limits. I'd like to know if M is also closed under the types of limit that involve a measure: "almost everywhere", "in measure" and "almost uniformly".
I think I have proved that if ##f## is a function from X into ##\mathbb C##, and ##\langle f_n\rangle_{n=1}^\infty## is a sequence in M such that ##f_n\to f## a.e., then there's a ##g\in M## such that f=g a.e. (I think I have also proved similar results for the other types of limit). If the two statements ##g\in M## and f=g a.e. together imply that ##f\in M##, this would mean that M is closed under a.e. limits. Is it?
Let ##(X,\Sigma,\mu)## be an arbitrary measure space. Let M be the set of measurable functions from X into ##\mathbb C##. I know that M is closed under pointwise limits. I'd like to know if M is also closed under the types of limit that involve a measure: "almost everywhere", "in measure" and "almost uniformly".
I think I have proved that if ##f## is a function from X into ##\mathbb C##, and ##\langle f_n\rangle_{n=1}^\infty## is a sequence in M such that ##f_n\to f## a.e., then there's a ##g\in M## such that f=g a.e. (I think I have also proved similar results for the other types of limit). If the two statements ##g\in M## and f=g a.e. together imply that ##f\in M##, this would mean that M is closed under a.e. limits. Is it?