Deformations of spacetime symmetries : gravity group valued momenta and non commutative fields Inhaltsverzeichnis: Invitation: gravity point particles and group valued momenta Gravity in 2+1 dimensions as a Chern Simons theory Gravity in 3+1 dimensions particles and topological limit Deformed classical particles: phase space and kinematics Hopf algebra relativistic symmetries: the k Poincarè algebra Classical fields symmetries and conserved charges Free quantum fields and discrete symmetries. Klappentext: This monograph provides an introduction to deformations of Poincaré symmetries focusing on models with a Lie group momentum space and associated non commutative space times. The emphasis is put on the emergence of such structures from quantum gravity their mathematical features described in terms of Hopf algebras and applications to particle kinematics and field theory. Part I of this work focuses on the link between gravity and deformed symmetries in the case of 2+1 and 3+1 space time dimensions. Part II is devoted to the description of classical particles with group valued momenta their phase spaces and kinematics. The last part of these notes provides an introduction to the basic features of classical and quantum field theory on κ Minkowski space time the prototypical example of non commutative space time exhibiting deformed Poincaré symmetry. The text being the first providing a detailed overview of these topics is primarily intended for researchers and graduate students interested in non commutative field theories and quantum gravity phenomenology.