https://popups.uliege.be/3041-539x/index.php?id=1524 Index terms fr 0 https://popups.uliege.be/3041-539x/index.php?id=1251 Infinite momentum frames (IMF) have been first introduced by J. Kogut and L. Susskind (1973) in the theory of partons. The concept of infinite momentum frames (IMF) have been developed by R. Dutheil (1984) on the basis of complex rotations group in a pseudo Euclidean space. In the present communication, we re-examine in section 2, the different definitions of IMF proposed by these authors : we criticize the not allowed renormalization of « divergent coordinates » done by J. Kogut and L. Susskind, we abstract the development by R. Dutheil of a two dimensional infinite momentum frame (IMF-2) from considerations on the subluminal and the superluminal Lorentz groups, we criticize the generalization to a four dimensional infinite momentum frame (IMF-4) proposed by R. Dutheil and G. Nibart. In section 3, we study the relativist transformations of two dimensional infinite momentum frames (IMF-2), which correspond to a subluminal Lorentz transformation or a superluminal Lorentz transformation. In section 4, we propose a new mathematical concept of IMF based on isotropic vectors and having any number of dimensions. In section 5, we re-examine the relativist quantum theory in IMF-2 developed by R. Dutheil, we propose a generalization of the Klein, Gordon and Fock equations in IMF-4, and we discuss the generalization by R. Dutheil of the Dirac equations to 4 dimensions. Wed, 10 Jul 2024 09:46:37 +0200 Mon, 07 Oct 2024 14:48:01 +0200 https://popups.uliege.be/3041-539x/index.php?id=1251 https://popups.uliege.be/3041-539x/index.php?id=1523 In a previous communication [1], G. NIBART (2001) has proposed a general definition of infinite momentum frames (IMF) from a mathematical point of view which allows to consider IMF with any number of dimensions. In the present communication, we try to build a new concept of space time with IMF. For this purpose, we study some assumptions about infinite momentum frames having n dimensions (IMF-n) : a) usual referential frames can be deduced from IMF-n (with n ≥ 4), b) IMF basis vectors can be associated to spinors. We also illustrate some particular IMF-n instances with the following examples: definition of spinors in an IMF-2, expression in an IMF-2 of the longitudinal Doppler effect including the case of tachyons, and application of IMF-6 to the "6 dimensional universe" [2] which has been defined by G. NIBART (2000). Mon, 15 Jul 2024 10:43:48 +0200 Mon, 15 Jul 2024 10:43:58 +0200 https://popups.uliege.be/3041-539x/index.php?id=1523