The map as a list

Ch. 1 Before the Universe

What lies outside our space and time?

10 families, 28 variants. Shares 25 theories with 6 other chapters.

• Mathematical & StructuralSpeculative2 variantsSpeculative
  • Mathematical Universe (Level IV) 1998 / 2007
  • Everettian Quantum Cosmology 1957
• Black Hole GenesisSpeculative4 variantsSpeculative
  • Afshordi's Holographic Big Bang 2014
  • Pathria-Good Black Hole Origin 1972
  • Popławski's Einstein-Cartan Torsion 2010 / 2016
  • Delayed Phase Transition Baby Universe 2025
• Quantum Tunneling OriginSpeculative6 variantsSpeculative
  • Vilenkin's Tunneling from Nothing 1982
  • Hartle-Hawking No-Boundary 1983
  • The Boundary Proposal 2024
  • Wormhole Nucleation from Anti-de Sitter 2024 / 2026
  • Tryon Vacuum Fluctuation 1973Historical
  • Gott-Li Self-Creating Universe 1998Historical
• Eternal InflationSpeculative3 variantsSpeculative
  • Linde's Chaotic Eternal Inflation 1986
  • String Theory Landscape 2003
  • Guth's Original Inflation 1980Historical
• Quantum Vacuum MechanismSpeculative1 variantSpeculative
  • Coleman-De Luccia Bubble Nucleation 1980
• Cyclic & Bouncing CosmologiesSpeculative6 variantsSpeculative
  • Loop Quantum Big Bounce 2001
  • String-Gas Cosmology 1989
  • Pre-Big Bang (Gasperini-Veneziano) 1993
  • Ekpyrotic Cyclic Universe 2001
  • Conformal Cyclic Cosmology (CCC) 2005
  • Simple Big Bounce various
• Cosmological SelectionSpeculative1 variantSpeculative
  • Smolin's Cosmological Natural Selection 1992
• Braneworld & the BulkSpeculative2 variantsSpeculative
  • Randall-Sundrum 1999
  • ADD Large Extra Dimensions 1998
• Alternatives to InflationSpeculative1 variantSpeculative
  • Varying Speed of Light 1999
• Time-Symmetric CosmologiesSpeculative2 variantsSpeculative
  • Janus Universe 2018
  • Boyle-Turok CPT-Symmetric Universe 2021 / 2024

Ch. 2 The Origin of Our Universe

How did our universe begin?

6 families, 15 variants. Shares 19 theories with 3 other chapters.

• Standard Big BangConsensus1 variantConsensus
  • Standard Big Bang Model 1927 / 1965
• Inflationary Big BangStrongly supported6 variantsStrongly supported
  • Modern Slow-Roll Inflation 1983 / 2018
  • Starobinsky R-squared Inflation 1980
  • Warm Inflation 1995 / 2020
  • Higgs Inflation 2008
  • Old Inflation 1980 / 1981Historical
  • New Inflation 1982Historical
• CPT-Symmetric UniverseSpeculative1 variantSpeculative
  • Boyle-Finn-Turok CPT Universe 2018
• Plasma-Based Alternative CosmologiesFringe3 variantsFringe
  • Peratt Plasma Structure Formation 1986
  • Alfvén-Klein Ambiplasma Cosmology 1960sHistorical
  • Lerner Plasma Universe 1991 / 2022Rejected
• Tired LightHistorical2 variantsHistorical
  • Zwicky Original Tired Light 1929Rejected
  • Modern Tired Light Revivals 1990s / 2010sRejected
• Steady StateHistorical2 variantsHistorical
  • Bondi-Gold-Hoyle Steady State 1948Rejected
  • Quasi-Steady-State Cosmology 1993Rejected

Ch. 3 The Nature of Space & Time

Is spacetime fundamental, or does it emerge from something deeper?

6 families, 22 variants. Shares 14 theories with 5 other chapters.

• Loop Quantum GravityFrontier2 variantsFrontier
  • Canonical / Spin-Foam Loop Quantum Gravity 1986
  • Loop Quantum Cosmology 2001
• Causal Set TheoryFrontier5 variantsFrontier
  • Sorkin's Causal Set Program 1987
  • Continuum Correspondence 1987 / 2013-2019
  • Phenomenology, Lorentz Tests and the Cosmological Constant 1991 / 2004
  • Classical Sequential Growth Dynamics 1999
  • Quantum Dynamics and the BDG Action 2010 / 2013-2018
• Emergent Spacetime & GravityFrontier5 variantsFrontier
  • Holographic Spacetime 1997 / 2010
  • Thermodynamics of Spacetime 1995
  • AdS/CFT Correspondence 1997 / 1998
  • Banks-Fischler Holographic Space-Time 2001 / 2020
  • Verlinde Entropic Gravity 2011 / 2017
• Causal Dynamical TriangulationFrontier4 variantsFrontier
  • Foundational CDT Program 1998
  • Emergent Universe, Phase Structure and de Sitter 2004
  • Quantum Microstructure and the Spectral Dimension 2005
  • Locally Causal CDT and Matter Coupling 2013
• Deformed Special RelativitySpeculative3 variantsSpeculative
  • Amelino-Camelia's Doubly Special Relativity 2002
  • Magueijo-Smolin Doubly Special Relativity 2002
  • Relative Locality 2011
• Hořava-Lifshitz GravitySpeculative3 variantsSpeculative
  • Original Hořava Formulation 2009
  • Consistent Extension (BPS) 2009 / 2011
  • Foundational Analysis (Sotiriou-Visser-Weinfurtner) 2009

Ch. 4 A Theory of Everything

Can all forces and particles be unified?

7 families, 27 variants. Shares 6 theories with 3 other chapters.

• Twistor TheoryFrontier4 variantsFrontier
  • Original Twistor Program 1967 / 1968
  • Twistor String Theory 2004
  • Amplituhedron and Positive Geometry 2014
  • Modern Twistor Methods 2017
• Grand Unified TheoriesFrontier4 variantsFrontier
  • SO(10) Unification 1975
  • Pati-Salam Model 1974
  • Supersymmetric SU(5) 1981
  • Georgi-Glashow SU(5) 1974Rejected
• Asymptotic SafetyFrontier5 variantsFrontier
  • Asymptotic Safety (Quantum Einstein Gravity) 1979 / 1998
  • Higher-Derivative Gravity Extensions 1977
  • Conformally Reduced Gravity 2009
  • Matter-Coupled Asymptotic Safety 2010
  • Lorentzian Asymptotic Safety 2025
• String TheoryFrontier5 variantsFrontier
  • Superstring Theory 1984
  • Heterotic Compactifications 1985
  • M-Theory 1995
  • F-Theory 1996
  • Swampland Program 2005
• Non-Commutative GeometryFrontier4 variantsFrontier
  • Connes-Chamseddine Spectral Action 1996
  • Standard Model with Neutrino Mixing 2006 / 2007
  • Spectral Pati-Salam Unification 2013
  • Deformed Hopf Algebra Neutrino Sector 2014
• Beneath the Standard ModelSpeculative2 variantsSpeculative
  • Oppenheim's Post-Quantum Classical Gravity 2023
  • Vanchurin's Neural Network Universe 2020
• Wolfram Physics ProjectFringe3 variantsFringe
  • Hypergraph Rewriting Model 2020
  • Multiway Systems and Quantum Mechanics 2020
  • Relativistic and Gravitational Properties 2020

Ch. 5 The Dark Universe

What is the universe really made of?

8 families, 27 variants. Shares 14 theories with 5 other chapters.

• Standard Cosmological ModelConsensus3 variantsConsensus
  • Plain ΛCDM 1998 / 2020
  • wCDM, constant equation of state 1997
  • w0waCDM, evolving dark energy 2001 / 2003
• Dark Matter CandidatesFrontier7 variantsFrontier
  • WIMPs 1977 / 1996
  • Primordial Black Holes 1974 / 1975
  • Axions and axion-like particles 1977 / 1983
  • Sterile Neutrinos 1994 / 1999
  • Self-Interacting Dark Matter (SIDM) 2000 / 2018
  • Fuzzy Dark Matter 2000
  • Superfluid Dark Matter 2015
• Modified Gravity / MONDFrontier4 variantsFrontier
  • MOND, Original Phenomenological Law 1983
  • TeVeS (Tensor-Vector-Scalar) 2004
  • Moffat MOG (Scalar-Tensor-Vector Gravity) 2006
  • Skordis-Złośnik Aether Scalar-Tensor 2021
• Dark Energy CandidatesFrontier6 variantsFrontier
  • Quintessence 1988 / 1998
  • K-essence 2000
  • Coupled Quintessence 2000
  • Phantom Energy 2002 / 2003
  • Holographic Dark Energy 2004
  • Chaplygin Gas 2001 / 2002Rejected
• Hubble Tension SolutionsFrontier1 variantFrontier
  • Early Dark Energy 2016 / 2019
• Large-Distance Modified GravitySpeculative3 variantsSpeculative
  • dRGT Massive Gravity 2011
  • DGP Self-Accelerating Branch 2000Rejected
  • Galileon Gravity 2009Rejected
• Geometric Modified GravitySpeculative2 variantsSpeculative
  • Hu-Sawicki f(R) 2007
  • Starobinsky Late-Time f(R) 2007
• Dark Energy SkepticsSpeculative1 variantSpeculative
  • Sarkar's Anisotropic Universe 2019

Ch. 6 Black Holes

What happens inside a black hole?

3 families, 17 variants. Shares 11 theories with 4 other chapters.

• Hawking RadiationStrongly supported4 variantsStrongly supported
  • Hawking Radiation (Original) 1974 / 1975
  • Primordial Black Hole Evaporation 1974
  • Analog Hawking Radiation and Trans-Planckian Concerns 1981 / 1991 / 2016
  • Hawking Radiation in Quantum Gravity Programs 2000-2025
• Singularity AlternativesFrontier6 variantsFrontier
  • Regular Black Holes (Bardeen-Hayward) 1968 / 2006
  • Kerr Inner Structure and Mass Inflation 1990
  • Quantum Bounce 2000 / 2006 / 2020
  • Gravastars 2001 / 2004
  • Fuzzballs (Geometric Replacement) 2005 / 2022
  • Planck Stars 2014
• Black Hole Information ParadoxFrontier7 variantsFrontier
  • Black Hole Complementarity 1993
  • Page Curve, Islands and Replica Wormholes 1993 / 2019
  • Fuzzballs 2005
  • Firewall Paradox 2013
  • ER = EPR 2013
  • Soft Hair 2016
  • Hawking's Information Loss 1976Historical

Ch. 7 The Fate of the Universe

How will our universe end?

5 families, 14 variants. Shares 8 theories with 2 other chapters.

• Heat Death and Eternal ExpansionConsensus3 variantsConsensus
  • Standard ΛCDM Heat Death 1997 / 2000
  • de Sitter Equilibrium 1977 / 2004
  • Quintessence Freeze Future 2005
• Vacuum DecayFrontier1 variantFrontier
  • Higgs Vacuum Decay 2013
• Recollapse and the Big CrunchSpeculative3 variantsSpeculative
  • Dynamical Dark Energy Turnaround 2002
  • Negative Cosmological Constant Recollapse 2002
  • Classical Closed Recollapse 1922Rejected
• Rip ScenariosSpeculative4 variantsSpeculative
  • The Big Rip 2003
  • The Little Rip 2011
  • The Pseudo-Rip 2012
  • Little Sibling of the Big Rip 2015
• Exotic Future SingularitiesSpeculative3 variantsSpeculative
  • Sudden Future Singularity 2004
  • The Big Brake 2004
  • Type III and Type IV Singularities 2005

Inflation answers both

Ch. 1 Before the Universe and Ch. 2 The Origin of Our Universe, 14 theories

• Boyle-Finn-Turok CPT Universe 2018, from Ch. 2
• Linde's Chaotic Eternal Inflation 1986, from Ch. 1
• Vilenkin's Tunneling from Nothing 1982, from Ch. 1
• Loop Quantum Big Bounce 2001, from Ch. 1
• Ekpyrotic Cyclic Universe 2001, from Ch. 1
• Afshordi's Holographic Big Bang 2014, from Ch. 1
• Smolin's Cosmological Natural Selection 1992, from Ch. 1
• Coleman-De Luccia Bubble Nucleation 1980, from Ch. 1
• Delayed Phase Transition Baby Universe 2025, from Ch. 1
• Hartle-Hawking No-Boundary 1983, from Ch. 1
• Pre-Big Bang (Gasperini-Veneziano) 1993, from Ch. 1
• Conformal Cyclic Cosmology (CCC) 2005, from Ch. 1
• Popławski's Einstein-Cartan Torsion 2010 / 2016, from Ch. 1
• Boyle-Turok CPT-Symmetric Universe 2021 / 2024, from Ch. 1

What spacetime really is

Ch. 1 Before the Universe and Ch. 3 The Nature of Space & Time, 7 theories

• Holographic Spacetime 1997 / 2010, from Ch. 3
• Thermodynamics of Spacetime 1995, from Ch. 3
• Verlinde Entropic Gravity 2011 / 2017, from Ch. 3
• Sorkin's Causal Set Program 1987, from Ch. 3
• Canonical / Spin-Foam Loop Quantum Gravity 1986, from Ch. 3
• Mathematical Universe (Level IV) 1998 / 2007, from Ch. 1
• Randall-Sundrum 1999, from Ch. 1

Strings and branes

Ch. 1 Before the Universe and Ch. 4 A Theory of Everything, 2 theories

• M-Theory 1995, from Ch. 4
• String Theory Landscape 2003, from Ch. 1

Braneworld cosmology

Ch. 1 Before the Universe and Ch. 5 The Dark Universe, 3 theories

• DGP Self-Accelerating Branch 2000, from Ch. 5
• Afshordi's Holographic Big Bang 2014, from Ch. 1
• Randall-Sundrum 1999, from Ch. 1

Universes born in black holes

Ch. 1 Before the Universe and Ch. 6 Black Holes, 5 theories

• Pathria-Good Black Hole Origin 1972, from Ch. 1
• Smolin's Cosmological Natural Selection 1992, from Ch. 1
• Afshordi's Holographic Big Bang 2014, from Ch. 1
• Delayed Phase Transition Baby Universe 2025, from Ch. 1
• Popławski's Einstein-Cartan Torsion 2010 / 2016, from Ch. 1

Cyclic time and false vacua

Ch. 1 Before the Universe and Ch. 7 The Fate of the Universe, 3 theories

• Coleman-De Luccia Bubble Nucleation 1980, from Ch. 1
• Conformal Cyclic Cosmology (CCC) 2005, from Ch. 1
• Ekpyrotic Cyclic Universe 2001, from Ch. 1

Wavefunction of the universe

Ch. 2 The Origin of Our Universe and Ch. 3 The Nature of Space & Time, 1 theory

• Loop Quantum Cosmology 2001, from Ch. 3

Hot Big Bang nucleosynthesis

Ch. 2 The Origin of Our Universe and Ch. 5 The Dark Universe, 4 theories

• Plain ΛCDM 1998 / 2020, from Ch. 5
• Quintessence 1988 / 1998, from Ch. 5
• Modern Slow-Roll Inflation 1983 / 2018, from Ch. 2
• Starobinsky R-squared Inflation 1980, from Ch. 2

Quantum gravity

Ch. 3 The Nature of Space & Time and Ch. 4 A Theory of Everything, 4 theories

• M-Theory 1995, from Ch. 4
• Canonical / Spin-Foam Loop Quantum Gravity 1986, from Ch. 3
• Foundational CDT Program 1998, from Ch. 3
• Holographic Spacetime 1997 / 2010, from Ch. 3

Emergent gravity

Ch. 3 The Nature of Space & Time and Ch. 5 The Dark Universe, 2 theories

• Verlinde Entropic Gravity 2011 / 2017, from Ch. 3
• Phenomenology, Lorentz Tests and the Cosmological Constant 1991 / 2004, from Ch. 3

Holography and ER=EPR

Ch. 3 The Nature of Space & Time and Ch. 6 Black Holes, 5 theories

• ER = EPR 2013, from Ch. 6
• Black Hole Complementarity 1993, from Ch. 6
• Page Curve, Islands and Replica Wormholes 1993 / 2019, from Ch. 6
• Holographic Spacetime 1997 / 2010, from Ch. 3
• Canonical / Spin-Foam Loop Quantum Gravity 1986, from Ch. 3

AdS/CFT, fuzzballs

Ch. 4 A Theory of Everything and Ch. 6 Black Holes, 1 theory

• ER = EPR 2013, from Ch. 6

Primordial black holes

Ch. 5 The Dark Universe and Ch. 6 Black Holes, 1 theory

• Primordial Black Hole Evaporation 1974, from Ch. 6

Dark energy decides the ending

Ch. 5 The Dark Universe and Ch. 7 The Fate of the Universe, 5 theories

• The Big Rip 2003, from Ch. 7
• Dynamical Dark Energy Turnaround 2002, from Ch. 7
• Phantom Energy 2002 / 2003, from Ch. 5
• Quintessence 1988 / 1998, from Ch. 5
• Holographic Dark Energy 2004, from Ch. 5