Particle theories with minimum observable length and open string theory

Some aspects of gravitational quantum mechanics

“…In the language of string theory one can say that a string cannot probe distances smaller than its length. The existence of such minimal observable length which is motivated from string theory [1][2][3][4][5][6][7], loop quantum gravity [8], quantum geometry [9] and black holes physics [10], leads to a generalization of Heisenberg uncertainty principle to incorporate gravitational induced uncertainty from very beginning. This feature constitutes a part of the motivation to study the effects of this modified algebra on various observables.…”

Nonlocal particles as strings

“…The same action was considered by Kato [5] long time ago as a particle action equivalent to the bosonic open string. Let us now derive this action from open string theory by integrating out the bulk degrees of freedom on the worldsheet, and show that this action is just the effective action for the boundary coordinates.…”

Higgs mechanism in nonlocal field theories

“…Second, the exponential factor of the d'Alembertian in eq. (1.1) is known to make mild the UV behavior of loop diagrams and thus has been studied not only in the context of string theory [11][12][13][14][15][16][17][18][19][20][21][22] but also as an alternative approach to quantum field theories and gravity [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42]. It is therefore interesting to study consistency of nonlocal field theories by themselves.…”