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Astronomy

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Astronomical Distance Units .
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Celestial Coordinates .
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Celestial Navigation .
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Location of North and South Celestial Poles .

Chemistry

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Avogadro's Number
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Balancing Chemical Equations
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Stochiometry
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The Periodic Table .

Classical Physics

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Archimedes Principle
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Bernoulli Principle
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Blackbody (Cavity) Radiation and Planck's Hypothesis
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Center of Mass Frame
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Comparison Between Gravitation and Electrostatics
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Compton Effect .
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Coriolis Effect
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Cyclotron Resonance
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Dispersion
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Doppler Effect
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Double Slit Experiment
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Elastic and Inelastic Collisions .
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Electric Fields
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Error Analysis
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Fick's Law
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Fluid Pressure
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Gauss's Law of Universal Gravity .
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Gravity - Force and Acceleration
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Hooke's law
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Ideal and Non-Ideal Gas Laws (van der Waal)
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Impulse Force
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Inclined Plane
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Inertia
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Kepler's Laws
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Kinematics
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Kinetic Theory of Gases .
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Kirchoff's Laws
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Laplace's and Poisson's Equations
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Lorentz Force Law
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Maxwell's Equations
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Moments and Torque
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Nuclear Spin
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One Dimensional Wave Equation .
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Pascal's Principle
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Phase and Group Velocity
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Planck Radiation Law .
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Poiseuille's Law
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Radioactive Decay
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Refractive Index
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Rotational Dynamics
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Simple Harmonic Motion
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Specific Heat, Latent Heat and Calorimetry
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Stefan-Boltzmann Law
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The Gas Laws
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The Laws of Thermodynamics
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The Zeeman Effect .
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Wien's Displacement Law
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Young's Modulus

Climate Change

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Keeling Curve .

Cosmology

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Baryogenesis
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Cosmic Background Radiation and Decoupling
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CPT Symmetries
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Dark Matter
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Friedmann-Robertson-Walker Equations
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Geometries of the Universe
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Hubble's Law
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Inflation Theory
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Introduction to Black Holes .
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Olbers' Paradox
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Penrose Diagrams
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Planck Units
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Stephen Hawking's Last Paper .
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Stephen Hawking's PhD Thesis .
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The Big Bang Model

Finance and Accounting

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Amortization
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Annuities
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Brownian Model of Financial Markets
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Capital Structure
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Dividend Discount Formula
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Lecture Notes on International Financial Management
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NPV and IRR
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Periodically and Continuously Compounded Interest
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Repurchase versus Dividend Analysis

Game Theory

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The Truel .

General Relativity

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Accelerated Reference Frames - Rindler Coordinates
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Catalog of Spacetimes .
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Curvature and Parallel Transport
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Dirac Equation in Curved Spacetime
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Einstein's Field Equations
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Geodesics
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Gravitational Time Dilation
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Gravitational Waves
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One-forms
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Quantum Gravity
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Relativistic, Cosmological and Gravitational Redshift
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Ricci Decomposition
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Ricci Flow
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Stress-Energy Tensor
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Stress-Energy-Momentum Tensor
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Tensors
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The Area Metric
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The Equivalence Principal
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The Essential Mathematics of General Relativity
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The Induced Metric
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The Metric Tensor
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Vierbein (Frame) Fields
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World Lines Refresher

Lagrangian and Hamiltonian Mechanics

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Classical Field Theory .
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Euler-Lagrange Equation
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Ex: Newtonian, Lagrangian and Hamiltonian Mechanics
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Hamiltonian Formulation .
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Liouville's Theorem
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Symmetry and Conservation Laws - Noether's Theorem

Macroeconomics

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Lecture Notes on International Economics
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Lecture Notes on Macroeconomics
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Macroeconomic Policy

Mathematics

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Amplitude, Period and Phase
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Arithmetic and Geometric Sequences and Series
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Asymptotes
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Augmented Matrices and Cramer's Rule
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Basic Group Theory
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Basic Representation Theory
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Binomial Theorem (Pascal's Triangle)
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Building Groups From Other Groups
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Completing the Square
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Complex Numbers
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Composite Functions
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Conformal Transformations .
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Conjugate Pair Theorem
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Contravariant and Covariant Components of a Vector
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Derivatives of Inverse Functions
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Double Angle Formulas
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Eigenvectors and Eigenvalues
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Euler Formula for Polyhedrons
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Factoring of a3 +/- b3
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Fourier Series and Transforms .
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Fractals
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Gauss's Divergence Theorem
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Grassmann and Clifford Algebras .
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Heron's Formula
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Index Notation (Tensors and Matrices)
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Inequalities
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Integration By Parts
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Introduction to Conformal Field Theory .
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Inverse of a Function
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Law of Sines and Cosines
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Line Integrals, ∮
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Logarithms and Logarithmic Equations
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Matrices and Determinants
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Matrix Exponential
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Mean Value and Rolle's Theorem
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Modulus Equations
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Orthogonal Curvilinear Coordinates .
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Parabolas, Ellipses and Hyperbolas
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Piecewise Functions
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Polar Coordinates
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Polynomial Division
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Quaternions 1
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Quaternions 2
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Regular Polygons
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Related Rates
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Sets, Groups, Modules, Rings and Vector Spaces
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Similar Matrices and Diagonalization .
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Spherical Trigonometry
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Stirling's Approximation
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Sum and Differences of Squares and Cubes
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Symbolic Logic
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Symmetric Groups
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Tangent and Normal Line
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Taylor and Maclaurin Series .
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The Essential Mathematics of Lie Groups
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The Integers Modulo n Under + and x
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The Limit Definition of the Exponential Function
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Tic-Tac-Toe Factoring
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Trapezoidal Rule
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Unit Vectors
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Vector Calculus
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Volume Integrals

Microeconomics

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Marginal Revenue and Cost

Particle Physics

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Feynman Diagrams and Loops
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Field Dimensions
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Helicity and Chirality
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Klein-Gordon and Dirac Equations
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Regularization and Renormalization
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Scattering - Mandelstam Variables
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Spin 1 Eigenvectors .
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The Vacuum Catastrophe

Probability and Statistics

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Box and Whisker Plots
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Categorical Data - Crosstabs
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Chebyshev's Theorem
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Chi Squared Goodness of Fit
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Conditional Probability
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Confidence Intervals
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Data Types
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Expected Value
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Factor Analysis
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Hypothesis Testing
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Linear Regression
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Monte Carlo Methods
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Non Parametric Tests
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One-Way ANOVA
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Pearson Correlation
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Permutations and Combinations
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Pooled Variance and Standard Error
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Probability Distributions
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Probability Rules
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Sample Size Determination
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Sampling Distributions
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Set Theory - Venn Diagrams
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Stacked and Unstacked Data
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Stem Plots, Histograms and Ogives
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Survey Data - Likert Item and Scale
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Tukey's Test
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Two-Way ANOVA

Programming and Computer Science

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Hashing
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How this site works ...
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More Programming Topics
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MVC Architecture
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Open Systems Interconnection (OSI) Standard - TCP/IP Protocol
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Public Key Encryption

Quantum Computing

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The Qubit .

Quantum Field Theory

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Creation and Annihilation Operators
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Field Operators for Bosons and Fermions
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Lagrangians in Quantum Field Theory
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Path Integral Formulation
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Relativistic Quantum Field Theory

Quantum Mechanics

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Basic Relationships
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Bell's Theorem
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Bohr Atom
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Clebsch-Gordan Coefficients .
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Commutators
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Dyson Series
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Electron Orbital Angular Momentum and Spin
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Entangled States
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Heisenberg Uncertainty Principle
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Ladder Operators .
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Multi Electron Wavefunctions
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Pauli Exclusion Principle
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Pauli Spin Matrices
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Photoelectric Effect
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Position and Momentum States
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Probability Current
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Schrodinger Equation for Hydrogen Atom
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Schrodinger Wave Equation
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Schrodinger Wave Equation (continued)
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Spin 1/2 Eigenvectors
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The Differential Operator
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The Essential Mathematics of Quantum Mechanics
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The Observer Effect
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The Quantum Harmonic Oscillator .
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The Schrodinger, Heisenberg and Dirac Pictures
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The WKB Approximation
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Time Dependent Perturbation Theory
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Time Evolution and Symmetry Operations
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Time Independent Perturbation Theory
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Wavepackets

Semiconductor Reliability

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The Weibull Distribution

Solid State Electronics

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Band Theory of Solids .
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Fermi-Dirac Statistics .
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Intrinsic and Extrinsic Semiconductors
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The MOSFET
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The P-N Junction

Special Relativity

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4-vectors .
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Electromagnetic 4 - Potential
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Energy and Momentum, E = mc2
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Lorentz Invariance
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Lorentz Transform
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Lorentz Transformation of the EM Field
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Newton versus Einstein
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Spinors - Part 1 .
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Spinors - Part 2 .
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The Lorentz Group
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Velocity Addition

Statistical Mechanics

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Black Body Radiation
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Entropy and the Partition Function
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The Harmonic Oscillator
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The Ideal Gas

String Theory

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Bosonic Strings
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Extra Dimensions
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Introduction to String Theory
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Kaluza-Klein Compactification of Closed Strings
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Strings in Curved Spacetime
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Toroidal Compactification

Superconductivity

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BCS Theory
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Introduction to Superconductors
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Superconductivity (Lectures 1 - 10)
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Superconductivity (Lectures 11 - 20)

Supersymmetry (SUSY) and Grand Unified Theory (GUT)

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Chiral Superfields
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Generators of a Supergroup
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Grassmann Numbers
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Introduction to Supersymmetry
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The Gauge Hierarchy Problem

The Standard Model

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Electroweak Unification (Glashow-Weinberg-Salam)
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Gauge Theories (Yang-Mills)
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Gravitational Force and the Planck Scale
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Introduction to the Standard Model
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Isospin, Hypercharge, Weak Isospin and Weak Hypercharge
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Quantum Flavordynamics and Quantum Chromodynamics
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Special Unitary Groups and the Standard Model - Part 1 .
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Special Unitary Groups and the Standard Model - Part 2
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Special Unitary Groups and the Standard Model - Part 3 .
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Standard Model Lagrangian
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The Higgs Mechanism
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The Nature of the Weak Interaction

Topology

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Units, Constants and Useful Formulas

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Constants
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Formulas
Last modified: January 26, 2018

Rotational Dynamics ---------------------- Centripetal Force: Centripetal force is defined as a force which keeps a body moving with a uniform speed along a circular path and is directed along the radius towards the centre. The magnitude of the centripetal force on an object of mass m moving at tangential speed v along a path with radius of curvature r is: F = mac = mv2/r The acceleration, ac is directed towards the center because the object is continually changing its direction as it moves around the circle. Proof: S = rcosθi + rsinθj d2S/dt2 = rcosθ(d2θ/dt2)i + rsinθ(d2θ/dt2)j = ω2(rcosθi + rsinθj) = rω2 since |rcosθi + rsinθj| = √(r2cos2θ + r2sin2θ) = r = v2/r since v =S/t = rθ/t = rω Example 1. Consider a rollercoater: At A: PE = mgh and KE = 0 At B: PE = 0 and KE = (1/2)mv2 At C: mv2/R = mg ∴ v2 = Rg Also, (1/2)mv2 = mg(h - 2R) substituting we get, R/2 = h - 2R ∴ h > 2.5R for the car to stay on the track. Example 2. Conical pendulum: Vertical component: Tcosθ = mg ∴ T = mg/cosθ Horizontal component: Tsinθ = mv2/r Substituting for T gives, mgsinθ/cosθ = mv2/r ∴ v = √(rgtanθ) = r√(g/h) Now v = 2πr/t ∴ t = T = 2π√(h/g) = 2π√(Lcosθ/g) for small θ, cosθ = 1 and the T is the same for the simple pendulum. Linear versus rotational comparison: Linear Rotational ----- ---------- x θ v ω (vtangential = 2πr/T) a α x = vt θ = ωt v = u + at ω = ωo + αt v2 = u2 + 2as ω2 = ω02 + 2αθ s = ut + (1/2)at2 ω = ωot + (1/2)αt2 m I F = ma τ = Iα p = mv L = Iω U = Fd U = τθ K = mv2/2 K = Iω2/2 W = Fd/t W = τθ/t Moment of Inertia of point mass: I = mr2 Angular Momentum: L = r x p = mvr = mr2ω = Iω ... (1) Angular Velocity: ω = Δθ/Δt = (1/r)Δs/Δt = v/r = 2π/T ... (2) Angular Acceleration: α = Δω/Δt = (1/r) Δv/Δt = a/r ... (3) Torque, τ: τ = Force x lever arm = FL The lever arm is defined as the perpendicular distance from the axis of rotation to the line of action of the force. L o --------- | \ |θ \ | \ | \ v \ F' F F' = Fcosθ Example 1. Consider the disc, rod and mass arrangement as shown. Assume, the I's are given or can be calculated. Tension in string: φ = 90 - θ ∴ cosφ = sinθ τMass = 2Rm1gsinθ τRod = Rm2gsinθ In equilibrium: τ = TR = 2Rm1gsinθ + Rm2gsinθ Angular acceleration of the disc after the string is cut: ITotal = IDisk + IRod + IMass α = τ/ITotal Linear acceleration of m1: From (3) a = α2R Linear velocity of m1 at the horizontal position: U = m1ghMass + m2ghRod KE = (1/2)Iω2 At horizontal: (1/2)Iω2 = m1ghMass + m2ghRod (1/2)Iω2 = 2Rm1gcosθ + Rm2gcosθ solve for ω From (2) v = ωR Example 2. Consider the above system. For the vertical pole assume: I = 0 and radius is r. Downward acceleration of M: Mg - T = Ma ∴ T = Mg - Ma τ = Iα = Tr ∴ T = Iα/r so Iα/r = Mg - Ma solve for a. Example 3. Translation velocity of cylinder at bottom of plane: (1/2)mv2 = mgh - (1/2)Iω2 but ω = v/r ∴ (1/2)mv2 = mgh - (1/2)Iv2/R2 solve for v. Linear acceleration of cylinder COM: mgsinθ - f = ma τ = fR = Iα From (3) fR = Ia/R => f = Ia/R2 ∴ mgsinθ - Ia/R2 = ma solve for a OR we could use v2 = u2 + 2as => v2 = 2as ∴ a = v2/2s = v2(2h/sinθ) Minimum μ for cylinder to roll without slipping: f = μmgcosθ ma = mgsinθ - f (cylinder just starts to slip when mgsinθ - f = 0 = mgsinθ - μmgcosθ a = gsinθ - μgcosθ solve for μ Example 3. Determine m2 for equilibrium: m2gr2 = m1gr1 solve for m2 Angular acceleration of cylinders after m2 removed: m1g - T = m1a ∴ T = m1(g - a) but a = αr ∴ T = m1(g - αr1) τ = Tr1 = m1(gr1 - αr12) = ITotalα Solve for α Tension in cable supporting m1: T = m1(g - αr1) Linear speed of m1 at the time it has descended h meters: mgh = (1/2)mv2 + (1/2)Iω2 but ω = v/r ∴ mgh = (1/2)mv2 + (1/2)Iv2/r2 Solve for v OR v2 = 2ah but a = αr1 ∴ v = √(2αr1h) OR ω2 = 2αθ but θ = h/r and v = rω ∴ v = √(2αr1h)