| String Theory |
Quantum Gravity |
1970s |
Leonard Susskind, Holger Bech Nielsen |
String theory posits that particles are one-dimensional strings rather than point-like objects. |
Indirectly supported through various predictions like black hole entropy. |
Loop Quantum Gravity |
| Loop Quantum Gravity |
Quantum Gravity |
1980s |
Carlo Rovelli, Lee Smolin |
Suggests that space is quantized and made of finite loops rather than continuous fabric. |
No direct experimental support yet; focuses on mathematical consistency. |
String Theory |
| Graviton Exchange |
Particle Physics |
1970s |
Richard Feynman, Steven Weinberg |
Proposes that gravity propagates via hypothetical massless particles called gravitons. |
Supported by quantum field theory but no direct evidence yet. |
Quantum Field Theory |
| Gravity as Geometry |
General Relativity Extension |
1915 |
Albert Einstein |
Gravity is a result of the curvature of spacetime caused by mass. |
Widely accepted through experimental evidence like light bending around stars. |
Graviton Hypothesis |
| M-Theory |
Unified Theory |
1995 |
Edward Witten |
An extension of string theory that includes 11 dimensions and unifies all string theories. |
Theoretical framework; not yet experimentally proven. |
String Theory |
| Supergravity |
Supersymmetry |
1976 |
S. Ferrara, D. Z. Freedman |
Combines supersymmetry with general relativity, predicting a graviton as a superpartner of the graviton. |
Lacks experimental support; theoretical basis is strong. |
String Theory |
| Hawking Radiation |
Black Hole Physics |
1974 |
Stephen Hawking |
Suggests that black holes emit radiation due to quantum effects near their event horizons, potentially involving gravitons. |
Indirectly supported by theories but no observation of black holes yet. |
Loop Quantum Gravity |
| Quantum Loop Gravity |
Quantum Gravity |
1990 |
Carlo Rovelli, Lee Smolin |
Proposes space is quantized and gravitational waves consist of loops of quantum space. |
No experimental confirmation; primarily a theoretical model. |
Loop Quantum Gravity |
| Perturbative Gravity |
Quantum Field Theory |
1960s |
Feynman, DeWitt |
Attempts to treat gravity as a perturbative field theory, making use of gravitons. |
Low energy predictions agree with classical gravity; high-energy behavior remains elusive. |
Quantum Field Theory |
| Emergent Gravity |
Theoretical Physics |
2010s |
Erik Verlinde |
Proposes that gravity is not a fundamental force but an emergent phenomenon from quantum entanglement. |
Not experimentally confirmed; still a developing field of thought. |
Quantum Gravity |
| Noncommutative Geometry |
Mathematical Physics |
1980s |
Alain Connes |
Uses noncommutative geometry to explain gravity and quantum phenomena, potentially involving gravitons. |
Mostly theoretical and lacks experimental verification. |
Loop Quantum Gravity |
| Gauge Theory of Gravity |
Field Theory |
1980s |
Kobayashi, Nakanishi |
Attempts to formulate gravity in the perspective of gauge theories, possibly leading to graviton-like behavior. |
Developments in theoretical physics but no direct experimental proof. |
Quantum Field Theory |
| Quantum Foam |
Quantum Gravity |
1970s |
John Wheeler |
Describes the fabric of spacetime at Planck scale, where fluctuations could involve gravitons. |
Not directly observable; speculative theory awaiting developments. |
Loop Quantum Gravity |
| Brane Worlds |
Higher Dimensional Theories |
1998 |
Lisa Randall, Raman Sundrum |
Suggests our 3D universe is a brane within a higher-dimensional space, influencing gravitational behavior. |
Indirect observations, like cosmological behavior, are being debated. |
String Theory |
| Simplicial Quantum Gravity |
Geometric Approach |
1980s |
Regge, Chern-Simons |
Models gravity using simplicial complexes and might lead to graviton-like structures. |
Theoretical framework with ongoing research; experimental links remain tenuous. |
Loop Quantum Gravity |
| Quantum Gravity Foam |
Theory of Quantum Gravity |
1980s |
John Archibald Wheeler |
Posits that spacetime is incredibly turbulent at the quantum level, potentially revealing gravitons. |
Not experimentally confirmed; purely theoretical concept. |
Loop Quantum Gravity |
| Fractal Spacetime |
Quantum Gravity |
1990s |
Michael Nielsen |
Proposes that the spacetime fabric is fractal and this topology could involve gravitons. |
Theoretical speculation, awaiting observational backing. |
Quantum Foam |
| Tensor Networks and Gravity |
Quantum Information Theory |
2010s |
Verlinde et al. |
Uses tensor networks to understand quantum gravity, suggesting connections to graviton behavior. |
Still theoretical with examination ongoing. |
Quantum Information Theory |
| Quantum Gravity via Causal Sets |
Theory of Quantum Gravity |
1990s |
Rafael Sorkin |
Poses that spacetime is made of a discrete set of events, potentially altering graviton dynamics. |
No experimental proof; mainly theoretical exploration. |
Loop Quantum Gravity |
| AdS/CFT Correspondence |
Theoretical Physics |
1997 |
Juan Maldacena |
Equates a theory of gravity in a space with a quantum field theory on the boundary, hinting at graviton implications. |
Currently theoretical; significant implications but lacking direct tests. |
String Theory |
| Torsion in Gravity |
Modified Gravity |
1940s |
Élie Cartan |
Involves torsion effects within spacetime potentially affecting graviton interactions. |
Speculative; lacks experimental evidence in current theories. |
Alternative Gravity Theories |
| Hidden Dimensions |
String Theory |
1980s |
Kaluza, Klein |
Postulates extra hidden dimensions that might influence gravitational interactions via gravitons. |
No experimental proofs yet; theoretical basis continues to grow. |
String Theory |
| Black Hole Information Paradox |
Quantum Information Theory |
1970s |
Stephen Hawking, Gary Horowitz |
Suggests issues with information retention in black holes, potentially linking to graviton dynamics. |
Debated; pending further investigation and observations. |
Quantum Gravity |
| Thermal States and Gravity |
Quantum Field Theory |
1990s |
Unruh, Hawking |
Examines thermodynamic properties of gravitation, including effects of gravitons at thermal scales. |
No concrete experimental backing; conceptual exploration. |
Quantum Statistical Mechanics |
| Entanglement and Gravity |
Quantum Information Theory |
2000s |
Renyi, Einstein |
Explores how quantum entanglement might affect gravitational interactions, particularly involving gravitons. |
Speculative; ongoing discussions exist. |
Quantum Mechanics |
| Quantum Gravity and Information |
Quantum Information Flow |
2000s |
Leonard Susskind |
Proposes links between quantum gravity and information flow, potentially implicating gravitons. |
Still a theoretical framework without direct experimental data. |
Quantum Gravity |
| Fuzzball Theory |
String Theory |
2000s |
Samir Mathur |
Describes black holes as 'fuzzy' objects with their entropy explained via strings, involving gravitons. |
No experimental support; remains a theoretical endeavor. |
String Theory |
| Modified Newtonian Dynamics (MOND) |
Alternative Gravity |
1983 |
Milgrom |
Attempts to explain galactic rotation without dark matter and might imply changes in graviton interaction. |
No mainstream acceptance; highly debated in scientific communities. |
Alternative Gravity Theories |
| Teleparallel Gravity |
Modified Gravity |
1990s |
Einstein |
Frames gravity in terms of torsion rather than curvature, positing changes in expected graviton behaviors. |
Primarily theoretical; experimental backing remains scant. |
Alternative Gravity Theories |
| Gravity's Rainbow |
Quantum Gravity |
2001 |
Magueijo, Smolin |
Proposes that the speed of light is variable at very high energies, affecting the behavior of gravitons. |
Theoretical basis vs. experimental data; ongoing discussions. |
Quantum Gravity |
| Quantum Field Theory on Curved Spacetime |
Quantum Gravity |
1960s |
Birrell, Davies |
Defines quantum fields in curved spacetime relevant for graviton interactions. |
Well-studied with some indirect experimental confirmation. |
General Relativity |
| Relational Quantum Mechanics |
Quantum Mechanics |
1995 |
Carlo Rovelli |
Posits that quantum mechanics is relational; this could influence graviton dynamics under certain conditions. |
Still a theoretical construct; no direct experimental evidence yet. |
Quantum Gravity |
| Quantum Gravity and Cosmology |
Cosmological Models |
2000s |
Bojowald |
Examines how quantum gravity could modify the early universe's expansion, potentially involving gravitons. |
Theoretical implications without current experimental validation. |
Loop Quantum Gravity |
| Group Field Theory |
Quantum Gravity |
2000s |
Oriti, Livine |
A framework that posits that spacetime is constructed from elementary building blocks, potentially leading to gravitons. |
Still a developing theoretical program; lacks experimental grounding. |
Loop Quantum Gravity |
| Symmetry in Gravity |
Quantum Gravity |
1990s |
Bardek et al. |
Involves symmetrical properties within the gravitational field which could modify graviton's role. |
Primarily theoretical; awaits observational tests. |
Quantum Field Theory |
| Path Integral Formulation of Gravity |
Quantum Gravity |
1980s |
Feynman, Hawking |
Utilizes path integrals to incorporate gravity into quantum mechanics, hinting at graviton dynamics. |
Theoretical; lacks experimental validation in multiple dimensions. |
Quantum Gravity |
| Quantum Harmonic Oscillator Under Gravity |
Quantum Mechanics |
1970s |
Rocco, Revnivtsev |
Analyzes how gravity alters the behavior of harmonic oscillators, hinting at graviton influence. |
Independently tested via quantum mechanics experiments; links still tenuous. |
Quantum Field Theory |
| Gravity and Simplicity |
Geometric Theory |
1990s |
Kauffman, Mazur |
Considers how gravity could emerge from simpler systems, perhaps indicating new graviton-like particles. |
Still in the exploratory phase; very few experimental connections exist. |
Quantum Gravity |
| Thermodynamics of Black Holes |
Black Hole Physics |
1974 |
Stephen Hawking |
Implies that black hole thermodynamics hint at structural dynamics involving gravitons. |
Attempts at verification through observational cosmology; debated outcomes. |
Loop Quantum Gravity |
| Instantons and Gravitons |
Quantum Field Theory |
1980s |
Gibbons, Hawking |
Examines role of instantons in the quantum gravity framework, potentially influencing graviton characteristics. |
Experimental support is absent; primarily theoretical contemplation. |
Quantum Field Theory |
| Nonlinear Gravity |
Modified Gravity |
1990s |
B. M. V. G. |
Studies how nonlinear aspects of gravity may reveal new particle interactions, possibly involving gravitons. |
Still theoretical; awaiting comprehensive validation. |
Alternative Gravity Theories |
| Gravity from Quantum Information |
Quantum Information Theory |
2020s |
Connes, Susskind |
Proposes gravity emerges from quantum information interactions, potentially involving gravitons. |
Emergent theories await experimental tests; discussions ongoing. |
Quantum Mechanics |
| Continuous Spacetime Hypothesis |
Mathematical Physics |
2010s |
Loll, Ambjorn |
Examines spacetime as continuous and how this might implicate interactions of gravitons. |
Theoretical conceptions mostly untested; reliant on mathematical frameworks. |
Loop Quantum Gravity |