There is an expression in English:
"For all I know, ...."
The following clause often has a modal expressing uncertainty or the hypothetical nature of the assertion, like "might", "may", "could", or "would".
For all I know, he might have gone abroad.
For all I know, she doesn't even work there anymore.
For all I know, the test hasn't even been written yet.
The usage is usually something like this. You are talking about some topic. You disavow even a basic level of certainty about the topic by saying "For all I know, X", meaning something like "I can't even be sure that X isn't true. How can I say anything useful about the topic, if I can't even rule out possibility X?"
This is not the same as "To the best of my knowledge, X" (which means you really think X, you are just saying you are unsure). I think that "As far as I know" is more like "To the best of my knowledge" than "For all I know", but I think it might have some flexibility. I don't know.
So, my question is whether Chinese has any equivalent phrases or ways to express "For all I know"? I've seen a few instances of
据我所知, but I don't know whether that's idiomatic Chinese or just a stilted and academic translation. Also, I don't know whether it really has any of the same implications that "For all I know" has. For all I know,
据我所知 is just a neutral statement like "To the best of my knowledge"!