I am writing a series about time travel to various different time eras across history while remaining scientifically accurate and I have a question about the method that the main characters use to do said time travel. In my search for said method, the closest real life equivalent to the rips in spacetime I've come up with were wormholes, which could (theoretically?) be a natural occurrence. In the realm of the series, they tend to spawn near points of higher gravity (Like on a planet or star), and or at weak points where the "fabric of spacetime" are. These rips would in turn create the wormholes which act as the actual method of transport.
I know that them being traversable without heavy protection is probably a stretch, but in other regards, is it too far off to say that these portals are close to accurate? If not, are there any alternate means that describe close to what I've thought up which I could use?
Thanks so much for taking the time to answer and discuss this with me. Have a nice day.