[Paper Review] A Unified View of the Basic Forces

Naresh Dadhich|ArXiv.org|May 12, 2006

Cosmology and Gravitation Theories7 references3 citations

TL;DR

This paper proposes that Einstein's general relativity, as a universal, long-range force interacting with all particles via energy, is the fundamental 'mother force' from which the other three basic forces—electromagnetic, weak, and strong—emerge by successively relaxing its two universal properties: universal linkage and long-range propagation. The key contribution is a unified framework suggesting duality between gravity and strong force, and between electromagnetism and weak force, with testable predictions including non-zero neutrino mass and right-handed electron coupling to the weak force.

ABSTRACT

In this essay we wish to seek a unifying thread between the basic forces. We propose that there exists a universal force which is shared by all that physically exists. Universality is characterized by the two properties: (i) universal linkage and (ii) long range. They uniquely identify Einstein gravity as the unversal force. All other forces then arise as these properties are peeled off. For instance, relaxing (i) but retaining (ii) will lead to Maxwell electromagnetic force. This unified outlook makes interesting suggestions and predictions: if there exists a new force, it can only be a short range non-abelian vector or a scalar field, and there should exist in an appropriate space duality relations between weak and electric, and between strong and gravity.

Motivation & Objective

• To identify a unifying principle underlying all fundamental forces based on universality.
• To explain how the electromagnetic, weak, and strong forces arise by peeling off the universal properties of gravity.
• To propose testable predictions about new physics, including neutrino mass and duality between forces.
• To suggest that unification may follow a pattern similar to electroweak unification, extending to gravity and strong force.

Proposed method

• Define universality via two properties: (i) universal linkage to all particles (massive and massless), and (ii) long-range propagation via a massless propagator.
• Identify Einstein gravity as the unique force satisfying both properties, derived from spacetime curvature and the Bianchi identity on the Riemann tensor.
• Derive the electromagnetic force by retaining long-range (massless) propagation but dropping universal linkage, leading to a U(1) Abelian vector field and Maxwell's equations.
• Derive the weak force by retaining universal linkage (to massive particles) but dropping long-range, resulting in a massive vector field with SU(2) symmetry.
• Derive the strong force by relaxing both properties, leading to a non-Abelian vector field with SU(3) symmetry and running coupling.
• Propose duality relations between gravity and strong force, and between electromagnetism and weak force, based on complementarity in linkage and range.

Experimental results

Research questions

• RQ1 What fundamental force uniquely satisfies both universal linkage and long-range propagation, and why is it identified as gravity?
• RQ2 How do the electromagnetic, weak, and strong forces emerge from gravity by successively relaxing its universal properties?
• RQ3 What are the implications for new physics if a new force exists, and what constraints does this framework impose on its nature?
• RQ4 Can duality relations exist between gravity and strong force, and between electromagnetism and weak force, based on their complementary properties?
• RQ5 What predictions does this unified framework make about neutrino mass and right-handed electron coupling to the weak force?

Key findings

• Einstein gravity is uniquely identified as the universal force due to its universal linkage to all particles and long-range propagation, derived from the Bianchi identity on the Riemann curvature tensor.
• The electromagnetic force arises as the unique non-universal, long-range force, corresponding to a massless U(1) Abelian vector field governed by Maxwell's equations.
• The weak force emerges as a partially universal, short-range force mediated by a massive vector boson with SU(2) symmetry, requiring non-zero neutrino mass.
• The strong force arises from a non-Abelian vector field with SU(3) symmetry and running coupling, lacking both universal linkage and long-range propagation.
• The framework predicts that right-handed electrons must couple to the weak force, despite current experimental non-observation, due to the requirement of partial universality.
• Duality relations are suggested between gravity and strong force, and between electromagnetism and weak force, based on their complementary properties in linkage and range.