Noncommutative Sp(2,R) Gauge Theories - A Field Theory Approach to Two-Time Physics

TL;DR

This paper develops noncommutative field theories with Sp(2,R) symmetry in phase-space, providing a field-theoretic formulation of two-time physics that unifies various fundamental fields and reveals dynamic spacetime signatures.

Contribution

It introduces a novel noncommutative Sp(2,R) gauge theory framework that captures two-time physics and unifies massless fields in reduced dimensions.

Findings

Spacetime signature is dynamically determined as (D-2,2).

Classical solutions encompass all known two-time physics results.

Unified treatment of massless scalar, gauge, gravitational, and higher-spin fields.

Abstract

Phase-space and its relativistic extension is a natural space for realizing Sp(2,R) symmetry through canonical transformations. On a Dx2 dimensional covariant phase-space, we formulate noncommutative field theories, where Sp(2,R) plays a role as either a global or a gauge symmetry group. In both cases these field theories have potential applications, including certain aspects of string theories, M-theory, as well as quantum field theories. If interpreted as living in lower dimensions, these theories realize Poincare' symmetry linearly in a way consistent with causality and unitarity. In case Sp(2,R) is a gauge symmetry, we show that the spacetime signature is determined dynamically as (D-2,2). The resulting noncommutative Sp(2,R) gauge theory is proposed as a field theoretical formulation of two-time physics: classical field dynamics contains all known results of `two-time physics', including the reduction of physical spacetime from D to (D-2) dimensions, with the associated `holography' and `duality' properties. In particular, we show that the solution space of classical noncommutative field equations put all massless scalar, gauge, gravitational, and higher-spin fields in (D-2) dimensions on equal-footing, reminiscent of string excitations at zero and infinite tension limits.