Striker Hope, 19, arrives from Everton having bagged four goals in 10 appearances for the Barclays Premier League club's Under-21 Development side this season.
Fellow forward German, 22, has found first-team opportunities hard to come by at parent club Gillingham this term, making eight substitute outings in Sky Bet League One.
Cobblers caretaker manager Andy King will welcome the additions to his injury-ravaged squad as he aims to haul the club off the bottom of League Two.
With Town's New Year's Day clash at home to Chesterfield postponed due to a waterlogged pitch, the new arrivals will be available to make their debuts in Saturday's trip to Newport.
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