# Physical meaning of the Feynman slash

In summary, the Feynman slash \slashed{a}=\gamma^\mu a_\mu maps a four-vector a to its Clifford algebra-representation, using the gamma matrices as expansion coefficients. It is commonly used in quantum field theory to write equations in a more compact form. It has also been used in merging quantum gravity and the Standard Model particle theory. However, our current LaTex version may no longer support the slash command.

The Feynman slash

$$\slashed{a}=\gamma^\mu a_\mu$$

maps a four-vector a to its Clifford algebra-representation. This is a linear combination of the gamma matrices with the components of a acting as expansion coefficients. What physical significance does this new object have?

The gamma matrices are used in the Dirac equation to take the formal square-root of the D'Alembertian operator. So can one interpret the slashed a as a formal square-root of a^2?

The Feynman slash

$$\slashed{a}=\gamma^\mu a_\mu$$

maps a four-vector a to its Clifford algebra-representation. This is a linear combination of the gamma matrices with the components of a acting as expansion coefficients. What physical significance does this new object have?

The gamma matrices are used in the Dirac equation to take the formal square-root of the D'Alembertian operator. So can one interpret the slashed a as a formal square-root of a^2?

I can't tell you the physical significance but the notation is evidently very convenient in quantum field theory and is used a lot. It allows equations to be written in more compact form. I looked up "feynman slash" in wikipedia and it gave a lot of examples and identities.
http://en.wikipedia.org/wiki/Feynman_slash_notation

Last edited:
Feynman slash plays a central role in this approach to merging quantum gravity and the Standard Model particle theory, by Chamseddine Connes and Mukhanov
http://arxiv.org/abs/1411.0977

Apparently our LaTex version used to support the " \slashed " command, but I think it may no longer do so. Maybe there is now a different command?

## 1. What is the Feynman slash?

The Feynman slash is a mathematical notation used in particle physics to represent the Dirac gamma matrices, which are operators that describe the spin and charge of particles. It is denoted by a slash through a vector or scalar quantity.

## 2. What is the physical meaning of the Feynman slash?

The physical meaning of the Feynman slash is that it represents the interaction between a particle and its antiparticle. It is used in Feynman diagrams to depict the exchange of virtual particles between particles, which can result in the creation or annihilation of particles.

## 3. Why is the Feynman slash important in particle physics?

The Feynman slash is important in particle physics because it allows for a concise and elegant representation of complex mathematical equations. It also helps to visualize and understand the interactions between particles in Feynman diagrams.

## 4. Is the Feynman slash used in other fields of science?

Yes, the Feynman slash notation is also used in other fields of science, such as quantum field theory and condensed matter physics. It is a useful tool for representing and solving equations involving spinor fields.

## 5. How does the Feynman slash relate to the Standard Model of particle physics?

The Feynman slash is an integral part of the Standard Model of particle physics, which is the current theory that describes the fundamental particles and their interactions. It is used to represent the interactions between particles in the Standard Model, such as the exchange of virtual photons in electromagnetic interactions.