Mathematical Foundations

Master the essential mathematics underlying general relativity, cosmology, and quantum gravity. From tensor calculus to differential geometry, functional analysis to Lie groupsβ€”all the tools you need for advanced gravitational physics.

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EigenChris: Tensor Calculus Series

The most popular visual introduction to tensors and differential geometry on YouTube! 43 comprehensive lectures covering everything from basic tensors through the Riemann curvature tensor.

Watch 43 Video Lectures→

Why These Mathematical Tools?

For General Relativity:

GR is fundamentally a geometric theory. You need tensor calculus to express physical laws in curved spacetime, differential geometry to understand manifolds and curvature, andvariational calculus to derive Einstein's equations from the Einstein-Hilbert action.

For Cosmology:

Cosmological models use differential geometry for the FLRW metric and spacetime symmetries.Lie groups describe the symmetries of homogeneous and isotropic spacetimes.Variational methods are essential for deriving equations of motion for scalar fields in inflation.

For Quantum Gravity:

Loop quantum gravity requires functional analysis for infinite-dimensional Hilbert spaces,Lie groups (especially SU(2)) for spin networks, and differential geometryfor connections and gauge theory. String theory uses complex analysis and conformal field theory.

Recommended Learning Path

1

Start with Tensor Calculus

Master index notation, Einstein summation, and basic tensor operations.

2

Move to Differential Geometry

Learn manifolds, metrics, connections, and curvatureβ€”the language of GR.

3

Study Variational Calculus

Understand action principles and how field equations are derived.

4

Explore Lie Groups & Symmetries

Learn gauge theory, symmetry groups, and their role in physics.

5

Advanced: Functional Analysis

For quantum gravity and quantum field theory in curved spacetime.