New Phenomena and New States of Matter in the Universe: From Quarks to Cosmos (374 Pages)

Recent discoveries in astronomy and relativistic astrophysics as well as experiments on particle and nuclear physics have blurred the traditional boundaries of physics. It is believed that at the birth of the Universe, a whirlwind of matter and antimatter, of quarks and exotic leptons, briefly appeared and merged into a sea of energy. The new phenomena and new states of matter in the Universe revealed the deep connection between quarks and the Cosmos. Motivated by these themes, this book discusses different topics: gravitational waves, dark matter, dark energy, exotic contents of compact stars, high-energy and gamma-ray astrophysics, heavy ion collisions and the formation of the quark–gluon plasma in the early Universe. The book presents some of the latest researches on these fascinating themes and is useful for experts and students in the field. Cover 1 Title page 4 Copyright 5 Dedication 6 Foreword 8 Preface 10 Contents 16 List of Figures 18 List of Tables 32 1. Cosmological Stochastic Gravitational Wave Background 34 1. Introduction 34 2. Inflation and Gravitational Waves 36 2.1. Pre-inflationary gravitational waves 44 3. Gravitational Waves from a Cyclic Universe 49 4. Gravitational Waves from the Electroweak Phase Transition 52 4.1. Thermodynamics of the EW transition 54 4.2. Generation of gravitational waves 56 5. Gravitational Waves from the QCD Phase Transition 60 5.1. Thermodynamics of the QCD phase transition 61 5.2. Generation of gravitational waves 63 5.3. A “crossover” QCD transition? 66 6. Detection Techniques 69 6.1. Detectors 71 6.2. Comparison with theoretical predictions 73 7. Final Considerations 76 Bibliography 80 2. Neutrino Flavor Oscillations in Gamma-Ray Bursts 86 1. Introduction 87 2. Hydrodynamics 89 2.1. Units, velocities and averaging 89 2.2. Conservation laws 93 2.3. Equations of state 96 3. Equations of Oscillation 101 4. Initial Conditions and Integration 108 5. Results and Analysis 111 6. Concluding Remarks 126 A. Appendix 132 A.1. Transformations and stress–energy tensor 132 A.2. Neutrino interactions and cross-sections 136 A.2.1. Neutrino emissivities 136 A.2.2. Cross-sections 139 A.3. Neutrino–anti-neutrino pair annihilation 141 Bibliography 142 3. Gamma-Rays and the New Multi-messenger Astrophysics 150 1. Introduction 151 2. The Crab Anniversary 152 2.1. The success of the imaging atmospheric technique 153 3. The First Gamma-ray Bursts at sub-TeV Energies 156 3.1. Late-afterglow GRB detections by H.E.S.S. 157 3.2. Early-afterglow detection of GRB 190114C 158 3.3. The short Gamma-ray burst GRB 160821B 160 4. The Era of Multi-messenger Astrophysics 161 4.1. Blazars as potential counterparts to VHE neutrinos 161 4.2. Gravitational wave follow-ups 162 5. The Roaring Twenties 163 5.1. The Cherenkov Telescope Array 164 5.2. Coming of age of wide-field facilities 168 5.3. Mapping the sky with HAWC 169 5.4. The upcoming LHAASO observatory 170 5.5. SWGO: A southern wide-field gamma-ray observatory 172 6. Conclusions 174 Acknowledgments 175 Bibliography 176 4. Dark Matter and Dark Energy vs. Modified Gravity: An Appraisal 180 1. Introduction 181 2. Ontological Preliminaries 183 3. Dark Matter 184 3.1. Observational evidence 184 3.2. Theoretical constraints 187 3.3. Dark matter candidates 189 3.4. Current limits 192 3.5. Observational evidence against dark matter 193 4. Dark Energy 194 4.1. Observational support 194 4.2. Vacuum energy density and the cosmological constant 196 4.3. Candidates for dark energy 198 4.3.1. Quintessence 198 4.3.2. k-essence 201 4.3.3. Unified models of dark energy and dark matter: The Generalized Chaplygin gas model 202 4.4. Current limits 203 5. Alternative Theories of Gravitation 206 5.1. The landscape of modified gravity theories 207 5.1.1. Scalar–Tensor–Vector Gravity 210 5.1.2. f(R)-gravity 215 5.2. Theoretical challenges 220 5.2.1. Scalar–Tensor–Vector Gravity 220 5.2.2. f(R)-gravity 222 6. Final Remarks 223 Acknowledgments 224 Bibliography 225 5. Hot Neutron Star Matter and Proto-neutron Stars 232 1. Introduction 233 2. Modeling Hot and Dense Neutron Star Matter 237 2.1. The nonlinear nuclear Lagrangian 237 2.2. Baryonic field theory at finite density and temperature 239 3. Composition and EOS of Hot and Dense (Proto-) Neutron Star Matter 243 3.1. Leptons and neutrinos 246 3.2. Chemical equilibrium and electric charge neutrality 246 3.3. Composition of hot and dense matter 250 4. The Hadron–Quark Phase Transition 257 5. The Parameters of the Hadronic Theory 261 5.1. The meson–hyperon coupling space 262 5.2. Δ(1232) isobars 263 5.3. The meson–Δ(1232) coupling spaces 266 5.3.1. The σωΔ coupling space 267 5.3.2. The xρΔ coupling 271 6. General Relativistic Stellar Structure Equations 272 6.1. Non-rotating proto-neutron stars 273 6.2. Rotating proto-neutron stars 275 6.2.1. The general relativistic Kepler frequency 275 6.2.2. Gravitational radiation–reaction-driven instabilities 278 6.3. The moment of inertia 280 7. Future Directions of Research 282 Acknowledgments 284 Bibliography 284 6. Review on the Pseudo-complex General Relativity and Dark Energy 294 1. Introduction 294 2. Pseudo-complex General Relativity (pc-GR) 296 3. Applications 301 3.1. Motion of a particle in a circular orbit 301 3.2. Accretion disks 303 3.3. Gravitational waves in pc-GR 306 3.4. Dark energy in the universe 308 3.5. Interior of stars 310 4. Conclusions 313 Acknowledgment 313 Bibliography 313 7. Alternative Gravity Neutron Stars in the Gravitational Wave Era 318 1. Introduction 319 2. Alternative Gravity Theories 324 2.1. Geometric trinity of gravity 324 2.1.1. Curvature theories 325 2.1.2. Torsion theories 327 2.1.3. Non-metricity theories 329 3. Stellar Equilibrium Configurations 331 4. Gravitational Wave Constraints 337 5. Discussion and Perspectives 339 Acknowledgment 339 Bibliography 340 8. Quark Deconfinement in Compact Stars Through Sexaquark Condensation 350 1. Introduction 350 2. Bose-Einstein Condensation of Sexaquarks as a Trigger for Strange Quark Matter in Compact Stars 352 3. Density Functional Approach to Strange Quark Matter Deconfinement 359 4. Conclusions 371 Acknowledgement 372 Bibliography 372