# Photon Acceleration by Superluminal Ionization Fronts

## Abstract

**:**

## 1. Introduction

## 2. Time Frame

## 3. Frequency Shifts

## 4. Field Transformations

## 5. Modulated Fronts

## 6. Conclusions

## Funding

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 1.**Superluminal ionization fronts, (

**a**) in the laboratory frame S and (

**b**) in the time frame ${S}^{\prime}$, for a simple front (in red) and a modulated front (in blue).

**Figure 2.**Frequency shifts for the transmitted and reflected beams, ${\omega}_{t}^{2}/{\omega}_{p0}^{2}$ (in blue) and ${\omega}_{r}^{2}/{\omega}_{p0}^{2}$ (in red), as a function of the frame velocity $\beta =V/c=c/u$ for an incident frequency ${\omega}_{i}=\sqrt{2}{\omega}_{p0}$.

**Figure 3.**Transmission and reflection coefficients: in the moving frame, ${T}^{\prime}$ (in blue) and ${R}^{\prime}$ (in red), as a function of ${\alpha}^{\prime}={\omega}_{t}^{\prime}/{\omega}_{i}^{\prime}$. The quantity ${T}^{\prime}+{R}^{\prime}$ is also represented (in black).

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**MDPI and ACS Style**

Mendonça, J.T.
Photon Acceleration by Superluminal Ionization Fronts. *Symmetry* **2024**, *16*, 112.
https://doi.org/10.3390/sym16010112

**AMA Style**

Mendonça JT.
Photon Acceleration by Superluminal Ionization Fronts. *Symmetry*. 2024; 16(1):112.
https://doi.org/10.3390/sym16010112

**Chicago/Turabian Style**

Mendonça, José Tito.
2024. "Photon Acceleration by Superluminal Ionization Fronts" *Symmetry* 16, no. 1: 112.
https://doi.org/10.3390/sym16010112