Nothing. Neither exists, they are both hypothetical dead ends to explain anomalies. Exotic matter is proposed to produce a 'negative energy' used to explain an argument first proposed when Alcubierre first designed the math of a warp bubble, that ... read more
Thus, exotic matter and the entire line of reasoning is nonsensical. Dark matter is another anomaly, the inability to explain more apparent mass in gravitational lensing and the way galaxies rotate then we see via telescope. Suffice it to say, every attempt to find dark matter has failed. Every attempt to explain it has failed. read more
Here I will explain the difference between matter, anti matter, dark matter, and negative matter in a concise and understandable way. I have seen confusion pop up in various online forums and comments on the recent announced trapping of an anti atom by CERN. read more
Exotic matter is assumed to be still matter that is not annihilating in contact with the standard matter. Anyway in this case it would be relatively easy to detect it. Candidates for this exotic matter are for example supersymmetric particles, WIMPS (weakly interacting massive particles) or axions. read more