Quantum Gravity and the Emergence of Spacetime
DOI:
https://doi.org/10.53573/rhimrj.2025.v12n7.009Keywords:
Quantum Gravity, Emergent Spacetime, Loop Quantum Gravity, String Theory, Holography, EntanglementAbstract
The incompatibility between general relativity and quantum mechanics has led to the formulation of quantum gravity, a splinter of theory that seeks to understand how to reconcile the geometric nature of one theory (gravity) with the probabilistic nature of the other (quantum mechanics). Current research on this issue has revealed an emerging consensus that spacetime is an emergent phenomenon, more than a fundamental one, and that it could have a more primitive quantum description. The paper explores the conceptual, mathematical, and philosophical bases of the emergence of spacetime in the major quantum gravity candidates, such as loop quantum gravity, string theory, holography, tensor networks, causal sets, and matrix models. The importance of how geometrical features, causal structure, and gravitational dynamics can be achieved by entanglement patterns, information constructs, or discrete algebraic systems is stressed. Such key mathematical constructions as the Wheeler DeWitt equation, spin network area operators, and Ryu Takayanagi's derived entropy expression are studied in an attempt to exemplify the formal foundations of emergence. Such unresolved issues as the reinstitution of classical spacetime, the status of time, and the experimental inaccessibility of Planck-scale phenomena are also considered in the discussion. By amalgamating different applications, the paper has made an association to the enhanced realization of how space and time may exhibit quantum origins, which represents a dramatic paradigm shift in theoretical physics.
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