In quantum field theory (QFT), gravity is described as the interaction between matter and spacetime curvature. In the framework of general relativity, gravity is understood as the curvature of spacetime caused by the distribution of mass and energy.
However, incorporating gravity into QFT is a challenging task. The conventional approach of quantizing gravity encounters significant difficulties, leading to the problem of non-renormalizability. This means that infinities arise in the calculations that cannot be removed through the usual renormalization techniques used in other quantum field theories.
The Higgs mechanism, on the other hand, is a mechanism in particle physics that explains how particles acquire mass. It was originally proposed to provide a mechanism for the masses of gauge bosons (W and Z bosons) in the electroweak theory. The Higgs mechanism introduces a new scalar field, called the Higgs field, that permeates all of spacetime.
In the electroweak theory, the Higgs field interacts with the gauge bosons and gives them mass through a process known as spontaneous symmetry breaking. The Higgs field has a nonzero vacuum expectation value, which breaks the electroweak symmetry and generates masses for the W and Z bosons while leaving the photon massless.
The connection between gravity, mass, and the Higgs mechanism lies in the fact that mass is a property of particles, and the Higgs field plays a role in the generation of mass. In the presence of the Higgs field, particles acquire mass through interactions with the Higgs boson. These masses are then incorporated into the equations of motion, including those of particles affected by gravity.
It is important to note that the Higgs mechanism does not directly explain gravity itself. The Higgs mechanism is a key ingredient in the Standard Model of particle physics, which describes three of the fundamental forces (electromagnetic, weak, and strong), but it does not encompass gravity. Gravity is currently described by general relativity, which is a classical theory of gravity and not a quantum field theory. Combining gravity with the principles of quantum field theory is an ongoing challenge in theoretical physics and is a topic of active research, with various approaches such as string theory and loop quantum gravity being pursued.