# Purely Virtual Particles in Quantum Gravity, Inflationary Cosmology and Collider Physics

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## Abstract

**:**

## 1. Introduction

## 2. Particles, Fakeons and Ghosts

## 3. Purely Virtual Particles: A New Diagrammatics

## 4. Quantum Gravity

## 5. Inflationary Cosmology from Quantum Gravity

#### 5.1. Cosmic RG flow

#### 5.2. Spectra

#### 5.3. Predictions

## 6. Phenomenology of Fake Particles

## 7. Peak Uncertainty and Micro Acausality

## 8. Conclusions

## Funding

## Conflicts of Interest

## References

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QFT RG Flow | Cosmic RG Flow | |
---|---|---|

RG flow | ↔ | slow roll |

couplings $\alpha $, $\lambda $ ... | ↔ | slow-roll parameters $\u03f5$, $\delta $ ... |

beta functions | ↔ | equations of the background metric |

sliding scale $\mu $ | ↔ | conformal time $\tau $ (or $\eta =-k\tau $) |

correlation functions | ↔ | perturbation spectra |

Callan-Symanzik equation | ↔ | RG equation at superhorizon scales |

RG invariance | ↔ | conservation on superhorizon scales |

asymptotic freedom | ↔ | de Sitter limit in the infinite past |

subtraction scheme | ↔ | Einstein frame, Jordan frame, etc. |

dimensional transmutation | → | $\tau $ drops out from the spectra, “replaced” by k |

running coupling | → | ok |

resummation of leading logs | → | ok |

anomalous dimensions | → | 0 |

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**MDPI and ACS Style**

Anselmi, D.
Purely Virtual Particles in Quantum Gravity, Inflationary Cosmology and Collider Physics. *Symmetry* **2022**, *14*, 521.
https://doi.org/10.3390/sym14030521

**AMA Style**

Anselmi D.
Purely Virtual Particles in Quantum Gravity, Inflationary Cosmology and Collider Physics. *Symmetry*. 2022; 14(3):521.
https://doi.org/10.3390/sym14030521

**Chicago/Turabian Style**

Anselmi, Damiano.
2022. "Purely Virtual Particles in Quantum Gravity, Inflationary Cosmology and Collider Physics" *Symmetry* 14, no. 3: 521.
https://doi.org/10.3390/sym14030521