• as far as I know, to my knowledge
• have cognizance of sg, have knowledge of sg, to be acquainted with sg, to be aware of sg, to be privy to sg
• to take cognizance of sg, to take notice of sg
• to be cognizant of sg, to be privy to sg
• to come to sy's knowledge, to come to sy's notice
• to become aware of sg, to get knowledge of sg, to obtain knowledge of sg
• it has come to my ear that
• to apprise sy of sg, to make sy aware of sg
• to ignore, to pass unmarked
• to be ignorant of sg, to be unaware of sg, to be unwitting of sg
• over sy's head, without asking sy