| heterotic e-string theory | has synonym E8 × E8 |   | 
| has definition One of the five superstring theories; involves closed strings whose right-moving vibrations resemble those of the Type II string and whose left-moving vibrations involve those of the bosonic string. Differs in important but subtle ways from the Heterotic-O string theory. |   | 
| is a kind of heterotic string theory |   | 
| theory | has validity correct or incorrect with caveats |   | 
| has author or reasearch group |   | 
| has domain a field of research |   | 
| has date or a range of dates for which the theory was active |   |