Paper P11Theory

MOO Invariance Under NNC Transforms

When is a Pareto front unchanged by transforming the objectives? Exactly when every objective is mapped by a strictly increasing function. Power transforms f^k on positive objectives qualify only for k > 0; for k < 0 they reverse every dominance relation.

Overview

Pareto dominance compares objectives only through the order relation <=. Any strictly increasing map g applied to each objective keeps that order, so the non-dominated set is the same before and after the transform. This is an elementary order-theory fact, not a property specific to non-Newtonian calculus.

A decreasing map flips every inequality: minimising g(f) then maximises f. The power transform f^k is increasing on f > 0 for k > 0 and decreasing for k < 0, so a k = -1 transform (the project default for 1/r cases) does not preserve the front; it turns a minimisation into a maximisation of the original objective.

The stored function-family analysis below classifies 0 of its 22 test functions as invariant (its own summary verdict), so it provides no empirical support for invariance either.

Stored Analysis

Mathematical Formulation

Power Transform

For a positive objective f(x) and k != 0:

T_k[f(x)] = exp(k * ln(f(x))) = f(x)^k

k = 1 is the identity; k > 0 is increasing; k < 0 is decreasing.

Pareto Dominance Preservation (k > 0 only)

For objectives f_i > 0 (minimization), if x dominates y:

f_i(x) <= f_i(y) for all i, with at least one strict inequality

k > 0: T_k[f_i(x)] <= T_k[f_i(y)] for all i, so x still dominates y

k < 0: T_k[f_i(x)] >= T_k[f_i(y)] for all i, so y now dominates x

Bounded Diagnostic (not regularization)

The log-bigeometric elasticity gives a bounded power-law diagnostic:

L_BG[1/r] = r * d/dr[ln(1/r)] = -1; D_BG[1/r] = exp(-1)

Bounded for r > 0, while the original 1/r field remains singular.

Key Results

Proposition (elementary)

For strictly increasing transforms of every objective, including T_k with k > 0 on positive objectives, the Pareto set is unchanged.

Counter-case: k < 0

T_k with k < 0 reverses dominance. Optimising a k = -1 transformed objective is a different problem, so this page gives no optimality guarantee for k < 0 searches.

Bijective on (0, infinity)

T_k is a bijection of the positive reals with inverse y^(1/k). It preserves order for k > 0 and reverses it for k < 0.

Stored Evidence

public/moo_invariance_analysis.json: summary n_invariant = 0 of 22 tested functions. The separate CASCADE toy benchmark is a synthetic distance-to-singularity exercise and says nothing about this proposition.

Related Pages

Technical Notes

  • - Objectives must be strictly positive (or shifted to a positive domain) for T_k to be defined
  • - Only k > 0 preserves the Pareto set; k < 0 reverses it
  • - Constraints are unaffected only if the same transform is not applied to them