In theoretical physics, paradoxes are good. That’s paradoxical, since a paradox appears to be a contradiction, and contradictions imply serious error. But Nature cannot realize contradictions. When our physical theories lead to paradox we must find a way out. Paradoxes focus our attention, and we think harder. When David Gross and I began the work that led to this Nobel Prize [1, 2, 3, 4], in 1...

astrophysics is becoming now an integral part of general physics. considering the black hole theory ,which is a new and exciting branch of relativistic astrophysics, we see many connections between elementary particle physics and astrophysics. in this article we attempt to explain the development of star physics ,in an easy ,understandable manner. previous knowledge of relativistic theory or cl...

In this article we have summarized the status of the system SANC version 0.41. We have implemented theoretical predictions for many high energy interactions of fundamental particles at the one-loop precision level for up to 4-particle processes. In the present part of our SANC description we place emphasis on an extensive discussion of an important first step of calculations of the one-loop amp...

The constrained Hamiltonian formalism is recommended as a means for getting a grip on the concepts of gauge and gauge transformation. This formalism makes it clear how the gauge concept is relevant to understanding Newtonian and classical relativistic theories as well as the theories of elementary particle physics; it provides an explication of the vague notions of “local” and “global” gauge tr...

In this article we have summarized the status of the system SANC version 0.41. We have implemented theoretical predictions for many high energy interactions of fundamental particles at the one-loop precision level for up to 4-particle processes. In the present part of our SANC description we place emphasis on an extensive discussion of an important first step of calculations of the one-loop amp...

The algebraic method of renormalization is applied to the standard model of electroweak interactions. We present the most important modifications compared to theories with simple groups. ∗ Presented at the DESY Zeuthen Workshop on Elementary Particle Theory “Loops and Legs in Gauge Theories”, Rheinsberg, Germany, April 19-24, 1998. (1) ALGEBRAIC RENORMALIZATION OF THE ELECTROWEAK STANDARD MODEL

We discuss the possible applications supersymmetric theories might nd in the eld of elementary particle physics. The supersymmetric generalization of the SU(3) SU(2) U(1) standard model is discussed in detail. Special attention has been devoted to the question of gauge coupling constant uni cation in the framework of supersymmetric grand uni ed models. * Lecture given at the conference "Gauge T...