[Paper Review] Strong Field Physics: Probing Critical Acceleration and Inertia with Laser Pulses and Quark-Gluon Plasma

Lance Labun, Johann Rafelski|arXiv (Cornell University)|Oct 10, 2010

Cold Atom Physics and Bose-Einstein Condensates7 references4 citations

TL;DR

This paper investigates strong field physics at critical acceleration—where particle dynamics approach the quantum vacuum instability threshold—using high-intensity laser pulses and quark-gluon plasma. It proposes that unit acceleration ($\dot{u} \to 1$ in natural units) reveals deep connections between radiation reaction, inertia, and quantum vacuum structure, suggesting a rethinking of classical and quantum dynamics with the vacuum as a universal inertial frame.

ABSTRACT

Understanding physics in domains of critical (quantum unstable) fields requires investigating the classical and quantum particle dynamics at the critical acceleration, $\\dot u \ o 1$ [natural units]. This regime of physics remains today experimentally practically untested. Particle and light collision experiments reaching critical acceleration are becoming feasible, in particular applying available high intensity laser technology. Ultra-relativistic heavy ion collisions breach the critical domain but are complicated by the presence of much other physics. The infamous problem of radiation reaction and the challenging environment of quantum vacuum instability arising in the high field domain signal the need for a thorough redress of the present theoretical framework.

Motivation & Objective

• To investigate the physical regime at critical acceleration ($\dot{u} \to 1$) where classical and quantum field theories break down due to vacuum instability and radiation reaction.
• To address the foundational problem of inertia by re-evaluating the role of the quantum vacuum as a universal inertial reference frame.
• To explore experimental feasibility of probing unit acceleration using high-intensity lasers and ultra-relativistic heavy ion collisions.
• To unify insights from quantum electrodynamics and quantum chromodynamics by identifying critical acceleration as a common frontier in strong field physics.
• To challenge the classical limit of quantum theory by incorporating vacuum dynamics and self-consistent radiation reaction into relativistic phase space formulations.

Proposed method

• Uses the Lorentz force equation $\frac{du^\alpha}{d\tau} = -\frac{e}{m}F^{\alpha\beta}u_\beta$ to define critical acceleration in natural units.
• Applies the critical electric field $E_c = \frac{m_e^2 c^3}{e\hbar} \approx 1.32 \times 10^{18}~\text{V/m}$ as a benchmark for strong field regimes.
• Analyzes laser pulse intensities up to $10^{24}~\text{W/cm}^2$, corresponding to $a_0 \sim 10^3$, to assess feasibility of reaching critical acceleration.
• Introduces the relativistic Wigner function formalism to derive a classical limit that includes vacuum dynamics and back-reaction effects.
• Compares radiation reaction in QED and QCD contexts, emphasizing cleaner access in QED due to simpler vacuum structure.
• Reinterprets the quantum vacuum as a modern 'aether'—a preferred inertial frame that may resolve long-standing issues in inertia and Mach's principle.

Experimental results

Research questions

• RQ1 What happens to particle dynamics when acceleration approaches the critical value $\dot{u} \to 1$ in natural units?
• RQ2 How can radiation reaction and vacuum instability be consistently incorporated into classical and quantum field theories at critical acceleration?
• RQ3 Can the quantum vacuum serve as a universal inertial reference frame, resolving the conceptual ambiguity in defining acceleration?
• RQ4 To what extent do high-intensity laser experiments and ultra-relativistic heavy ion collisions probe the same critical acceleration regime?
• RQ5 How does the inclusion of vacuum dynamics in the classical limit alter the standard Lorentz and Bargmann-Michel-Telegdi equations?

Key findings

• Critical acceleration $\dot{u} \to 1$ corresponds to $1.32 \times 10^{18}~\text{V/m}$, a field strength now approaching experimental reach via next-generation lasers.
• High-intensity lasers with $a_0 \sim 10^3$ can produce conditions where electrons experience accelerations near the critical threshold.
• The quantum vacuum becomes unstable to spontaneous pair production near $E_c$, signaling a breakdown of standard QED and classical electrodynamics.
• Radiation reaction becomes non-negligible at critical acceleration, challenging the self-consistency of classical electrodynamics.
• The relativistic Wigner function approach provides a framework to derive classical dynamics that include vacuum structure and back-reaction effects.
• The quantum vacuum may act as a preferred inertial frame, offering a resolution to the long-standing problem of defining inertia in relativistic and quantum theories.