Born in 1988 in Würzburg, Germany, Matthias Lienert studied physics in Göttingen and theoretical physics in Cambridge, UK. He obtained his PhD in Mathematics at Ludwig Maximilians University in Munich in 2015. Since then he has been a postdoctoral researcher in mathematical physics, in particular relativistic quantum theory, at Rutgers University, USA, and the University of Tübingen, Germany. Sören Petrat was born in 1985 in Castrop-Rauxel (Germany). After obtaining a PhD in mathematics from Ludwig Maximilians University Munich, he worked as a postdoctoral researcher at IST Austria, IAS Princeton, and Princeton University. Since 2017 he is Professor at Jacobs University Bremen. His field of research is mathematical physics, specifically many-body quantum mechanics and relativistic quantum physics.Roderich Tumulka was born in 1972 in Frankfurt am Main (Germany), earned a Ph.D. in mathematics from Ludwig Maximilians University in Munich, taught at Rutgers University (USA) in 2007—2016, and has since taught at Eberhard Karls University in Tübingen (Germany). His field of research is mathematical physics, particularly the foundations of quantum mechanics, quantum field theory, and quantum statistical mechanics.

• Introduction and Overview.- Consistency Conditions.- Relativistic Point Interactions.- Multi-Time Quantum Field Theory.- Interior-Boundary Conditions.- Born’s Rule.- Multi-Time Integral Equations.

Born in 1988 in Würzburg, Germany, Matthias Lienert studied physics in Göttingen and theoretical physics in Cambridge, UK. He obtained his PhD in Mathematics at Ludwig Maximilians University in Munich in 2015. Since then he has been a postdoctoral researcher in mathematical physics, in particular relativistic quantum theory, at Rutgers University, USA, and the University of Tübingen, Germany. Sören Petrat was born in 1985 in Castrop-Rauxel (Germany). After obtaining a PhD in mathematics from Ludwig Maximilians University Munich, he worked as a postdoctoral researcher at IST Austria, IAS Princeton, and Princeton University. Since 2017 he is Professor at Jacobs University Bremen. His field of research is mathematical physics, specifically many-body quantum mechanics and relativistic quantum physics.Roderich Tumulka was born in 1972 in Frankfurt am Main (Germany), earned a Ph.D. in mathematics from Ludwig Maximilians University in Munich, taught at Rutgers University (USA) in 2007—2016, and has since taught at Eberhard Karls University in Tübingen (Germany). His field of research is mathematical physics, particularly the foundations of quantum mechanics, quantum field theory, and quantum statistical mechanics.

• Introduction and Overview.- Consistency Conditions.- Relativistic Point Interactions.- Multi-Time Quantum Field Theory.- Interior-Boundary Conditions.- Born’s Rule.- Multi-Time Integral Equations.

Born in 1988 in Würzburg, Germany, Matthias Lienert studied physics in Göttingen and theoretical physics in Cambridge, UK. He obtained his PhD in Mathematics at Ludwig Maximilians University in Munich in 2015. Since then he has been a postdoctoral researcher in mathematical physics, in particular relativistic quantum theory, at Rutgers University, USA, and the University of Tübingen, Germany. Sören Petrat was born in 1985 in Castrop-Rauxel (Germany). After obtaining a PhD in mathematics from Ludwig Maximilians University Munich, he worked as a postdoctoral researcher at IST Austria, IAS Princeton, and Princeton University. Since 2017 he is Professor at Jacobs University Bremen. His field of research is mathematical physics, specifically many-body quantum mechanics and relativistic quantum physics.Roderich Tumulka was born in 1972 in Frankfurt am Main (Germany), earned a Ph.D. in mathematics from Ludwig Maximilians University in Munich, taught at Rutgers University (USA) in 2007—2016, and has since taught at Eberhard Karls University in Tübingen (Germany). His field of research is mathematical physics, particularly the foundations of quantum mechanics, quantum field theory, and quantum statistical mechanics.

• Introduction and Overview.- Consistency Conditions.- Relativistic Point Interactions.- Multi-Time Quantum Field Theory.- Interior-Boundary Conditions.- Born’s Rule.- Multi-Time Integral Equations.