Can the shape of our Universe be a Mobius strip?
137342
Can spacetime be non-orientable?
75788
Is spacetime absolute?
136811
Orbit space of torus homeomorphic to mobius strip
79708
Is the energy density of vacuum uniform in the whole universe?
58042
Redshifting of Light and the expansion of the universe
115517
How could we know that the relativistic curvature of universe is intrinsic?
98769
Find a universe and a predicate that satisfy the following formula
16647
Is the world $C^\infty$?
139471
What if the size of the Universe doubled?
112411
What happens when a photon reaches the "edge" of the universe?
58000
How can one show that a möbius transformation maps the unit circle to some axis?
101978
Are the implications of an infinite universe necessarily so unsettling
75070
Will the CMB eventually recede outside our observable universe?
87167
Do cosmological and Doppler redshift produce different patterns?
95681
If the universe is 3D, how is space-time like a "fabric"?
72416
The universe appears to have a lower bound in the time dimension, why not an upper bound?
20511
Is it possible to experimentally show that observable universe is much larger than ~93B ly?