Two Point Momentless (2PM)
2PM is a way of saying that reality doesn’t have a single, privileged “instant” from which everything starts. When we look closely—especially in quantum physics—what we call “a moment” is often just a convenient cut we make for calculation. Our recent publication proposes a cleaner view: instead of treating a single instant as the true beginning, we treat beginnings and endings as relational—defined by how conditions meet, not by a metaphysically solid “now.”
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The paper implements this idea inside the Schwinger–Keldysh / closed-time-path (SK/CTP) formalism by imposing a symmetry on the boundary description: swapping the two SK branches (\Phi_+,\Phi_-)\mapsto(\Phi_-,\Phi_+) must leave the preparation functional invariant, which in Keldysh variables corresponds to an evenness condition under \Phi_\Delta\to-\Phi_\Delta.
From there, it makes a practical claim: many different “memory/boundary” descriptions lead to the same predictions for a chosen set of observables S. That freedom lets us compress away unnecessary structure without changing what matters. This is formalized as the Minimal Sufficient Memory (MSM) principle: within the 2PM-admissible class, choose the simplest boundary representation that preserves the target predictive content. The paper demonstrates this explicitly in a solvable harmonic-oscillator setting and discusses existence/uniqueness in the Gaussian sector under standard convexity assumptions.
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