[John369 (OP)]

I know many of these haven't been proven and just derived from possibilities of physical theories, but please help me answer all of these questions:

1. Why would quantum corrections be infinite as one passes through a wormhole hence leading to lethal gravitational radiation? What calculation shows infinite quantum corrections?
2. What does it mean by a false vacuum representing a local minimum but not global minimum of energy? Can you give an example?
3. Please explain false vacuum decay event. And how it is used in doomsday event.
4. What is the flux vacuum in string theory?
5. Are all the possible ways things can be arranged also included in the multiverse, specifically type 4 of Tegmark's that is the ultimate ensemble saying all mathematical models count? But for 8K UHD resolution(7680x4320) or 33177600 pixels each pixel being filled with 48 bit color(so 2.81e+14 colors for one pixel) gives rise to (2.81*10^14)^33177600 number of different ways they could be arranged and hence 1 frame has (2.81*10^14)^33177600 or (2.81)^464486400 possible configurations, for a 60 fps and say 20 minute movie scene, this would be (2.81)^3.34e+13 possible number of configurations, in only 20 minutes, in a simple monitor, not even the universe or universe's age having been taken into account. This easily exceeds Tegmark's estimation that an idential Hubble voume to ours should be atleast (10^10)^115 or 10^1150 meters away from us and things would start to repeat. How do things start to repeat exactly? Even though just a 20 minute movie scene in some monitor could have (2.81)^3.34e+13 number of possible configurations? Does this mean the multiverse might contain atleast (2.81)^3.34e+13 number of possible universes based on some simple 20 minute movie scene alone? Does this count? Do every possible permutation of the universe count in a multiverse?
6. What is the estimated size of the whole universe? How can that be calculated?
7. Hubble constant value is around 70 km/s/Mpc(or 70 km/s/3.26e+6 light years), so considering the observer is at the center of observable universe(having radius 4.65e+10 light years), the 4.65e+10 light year objects are moving away from universe center at the rate of 1e+6 km/s. Is this correct? For Andromeda galaxy, this would give (1.75e+8 ly km/s)/(3.26e+6 ly) = 53.6 km/s. Is this correct?
8. In the brane multiverse model, 4D space-time universe branes are moving inside 10 dimensional hyperspace or 11 dimensional hyperspace? Should the hyperspace/bulk have temporal dimension? Is the bulk confined to time?
9. In the many-worlds interpretation of quantum mechanics, one universe keeps splitting into copies of itself, like the cat dead found in one universe with one timeline and the cat alive in a different universe with different timeline, all probabilities happen in different universes, does this mean all those universes aren't time displaced and continue to go towards the future of increasing entropy and eventually heat death for every universe? For example, one universe is 13.8 billion years old and another is 1e+100 years old when all black holes evaporated, can they co-exist in a multiverse of many-worlds interpretation?
10. Can there be an infinite number of dimensions? What is the upper limit and why are dimensions limited?
11. What does it mean to require Jupiter sized mass of exotic matter/negative energy for a 1 meter wide Visser wormhole? How is this calculated?
12. Please explain large extra dimensions.

[Kryptid]

I can't answer all of your questions, but I can answer some:

3. Please explain false vacuum decay event. And how it is used in doomsday event.

Space has some net energy density even when it is devoid of all matter. This may, or may not, represent the minimum possible energy of the vacuum. If it isn't the minimum energy, then it is possible for the vacuum to lose energy and thus transition into a true (or at least "more true") vacuum with a lower energy density than the original. Whether or not this will happen is down to probability because of quantum physics. Wait long enough, and it should happen.

This release of energy should spread throughout the entire Universe, starting at the point where the vacuum transitioned into a lower energy state. This would presumably take the form of a sphere expanding at the speed of light. Since the energy of the vacuum is lower inside of the sphere than outside, the laws of physics may also be different. If this is true, then matter (and even life) as we know it may not be possible inside of the sphere. So if the edge of the expanding sphere were to pass through our Solar System, it could result in the eradication of all life.

6. What is the estimated size of the whole universe? How can that be calculated?

This is unknown. If I remember correctly, different inflation models produce different values for the total size of the Universe. This paper suggests that it could be above 10 to the 10th to the 10th to the 122nd mega-parsecs across: https://arxiv.org/abs/hep-th/0610199

9. In the many-worlds interpretation of quantum mechanics, one universe keeps splitting into copies of itself, like the cat dead found in one universe with one timeline and the cat alive in a different universe with different timeline, all probabilities happen in different universes, does this mean all those universes aren't time displaced and continue to go towards the future of increasing entropy and eventually heat death for every universe? For example, one universe is 13.8 billion years old and another is 1e+100 years old when all black holes evaporated, can they co-exist in a multiverse of many-worlds interpretation?

The second law of thermodynamics is probabilistic in itself. It is extraordinarily likely to be held for complex systems because there are exponentially more ways that entropy can increase over time rather than decrease. However, a multiverse where literally every possibility is realized, then there would be quite a few where entropy runs, as least temporarily, backwards.

10. Can there be an infinite number of dimensions? What is the upper limit and why are dimensions limited?

In principle, I don't see why there should be an upper limit.

[John369 (OP)]

Thanks for the answer.

If in a multiverse every possibility is realized, would that also included all of the permutations of a universe? Does my pixel color arrangement example also get realized? Specially in the type 4 of Tegmark's in which every possible thing one can think of and describe mathematically is included? Would permutations of the universe also count in many-worlds interpretation? Would permutations count in type 1 of Tegmark's which is the extension to our own universe? Would this also count in type 2 of different physical constants and eternal inflation giving rise to many baby mini-universes?

In type 1 of Tegmark's, if there is just one infinite universe, things are stated to repeat and every event would occur an infinite number of times, however, why would all the Hubble volumes have the same physical laws and physical constants everywhere? Do the physical laws and constants differ in type 1?

[Kryptid]

Thanks for the answer.

If in a multiverse every possibility is realized, would that also included all of the permutations of a universe? Does my pixel color arrangement example also get realized? Specially in the type 4 of Tegmark's in which every possible thing one can think of and describe mathematically is included? Would permutations of the universe also count in many-worlds interpretation? Would permutations count in type 1 of Tegmark's which is the extension to our own universe? Would this also count in type 2 of different physical constants and eternal inflation giving rise to many baby mini-universes?

In type 1 of Tegmark's, if there is just one infinite universe, things are stated to repeat and every event would occur an infinite number of times, however, why would all the Hubble volumes have the same physical laws and physical constants everywhere? Do the physical laws and constants differ in type 1?

In an infinite multiverse, every single possibility should be manifested an infinite number of times. If you can imagine it, and it doesn't violate the laws of physics, then it should exist somewhere in an infinite multiverse. We don't know whether the laws of physics can actually be different or not. I've seen it proposed that different Hubble volumes could potentially have different laws of physics, but we don't know that.