If, for example, I throw an Ender Pearl in the Overworld then quickly teleport to The End, and assuming that there is someone to keep the chunks loaded, will I be teleported back?
So using a method from this post i kept about five chunks loaded. I can't prove if this make's sure that the chunks stay loaded but this is my method anyway:
I loaded a super-flat world and used the /setblock command to make an end portal and used the method above to make sure the chunks stay loaded. I then threw the ender pearl and jumped in to the portal. Nothing happened but please be aware that the chunks may not load as I'm not one hundred percent sure that SkylinerW's method is 100% accurate. I tried this method five times in a row with the same results.
Also sometimes during the commandblockoutput there would be an error but it's moving too fast for me to read it.
My Opinion is that it does not work, but may have worked in previous version's. I'm going to research this more.
But technically a player can teleport between dimensions simply by throwing one into an end portal.
When you throw an ender pearl through a portal it will go into that dimension just like any other entity. If you are in single player the chunks in that dimension will not be loaded so the ender pearl will not be moving. When you later go into that dimension the chunk with pearl will be loaded allowing it to move. (Unless you throw the ender pearl into one nether portal then enter another really far away.) When the pearl lands you will be teleported if you are in that dimension.
There is no way you can go from one dimension to another without entering the portal yourself. (Except if there is a way with commands.)
Actually they do work between dimensions. They only work in multiplayer though.
Let me explain: I build a teleporter with redstone and slime blocks that bounce the enderpearl in perfect sync so that when something breaks the signal the pearl falls on the block landing me there so I had my friend in one dimension and me on the other and he broke the signal and I teleported.