Roko's basilisk: a thought experiment which states that there could be an artificial superintelligence in the future that, while otherwise benevolent, would punish anyone who knew of its potential existence but did not directly contribute to its advancement or development, in order to incentivize that advancement.

Dark forest hypothesis: the idea that extraterrestrial civilizations may exist in abundance across the universe, but remain silent and hidden out of fear that revealing themselves would lead to destruction by a more technologically advanced and hostile civilization.[1] It is one of several proposed explanations of the Fermi paradox, which contrasts the high probability of extraterrestrial life with the lack of evidence for it.

[see 'The Dark Forest' by Liu Cixin]

Holographic universe: The holographic principle is a property of string theories and a supposed property of quantum gravity that states that the description of a volume of space can be thought of as encoded on a lower-dimensional boundary to the region – such as a light-like boundary like a gravitational horizon...

..."The three-dimensional world of ordinary experience—the universe filled with galaxies, stars, planets, houses, boulders, and people—is a hologram, an image of reality coded on a distant two-dimensional surface."

Simulation hypothesis: proposes that what one experiences as the real world is actually a simulated reality, such as a computer simulation in which humans are constructs....

...if a civilization becomes capable of creating conscious simulations, it could generate so many simulated beings that a randomly chosen conscious entity would almost certainly be in a simulation. 

This argument presents a trilemma:

1. either such simulations are not created because of technological limitations or self-destruction;

2. advanced civilizations choose not to create them;

3. if advanced civilizations do create them, the number of simulations would far exceed base reality and we would therefore almost certainly be living in one.