A tentative theory of large distance physics

A theoretical mechanism is devised to determine the large distance physics ofspacetime. It is a two dimensional nonlinear model, the lambda model, set togovern the string worldsurface to remedy the failure of string theory. Thelambda model is formulated to cancel the infrared divergent effects of handlesat short distance on the worldsurface. The target manifold is the manifold ofbackground spacetimes. The coupling strength is the spacetime couplingconstant. The lambda model operates at 2d distance $\Lambda^{-1}$, very muchshorter than the 2d distance $\mu^{-1}$ where the worldsurface is seen. A largecharacteristic spacetime distance $L$ is given by $L^2=\ln(\Lambda/\mu)$.Spacetime fields of wave number up to 1/L are the local coordinates for themanifold of spacetimes. The distribution of fluctuations at 2d distancesshorter than $\Lambda^{-1}$ gives the {\it a priori} measure on the targetmanifold, the manifold of spacetimes. If this measure concentrates at amacroscopic spacetime, then, nearby, it is a measure on the spacetime fields.The lambda model thereby constructs a spacetime quantum field theory, cutoff atultraviolet distance $L$, describing physics at distances larger than $L$. Thelambda model also constructs an effective string theory with infrared cutoff$L$, describing physics at distances smaller than $L$. The lambda model evolvesoutward from zero 2d distance, $\Lambda^{-1} = 0$, building spacetime physicsstarting from $L=\infty$ and proceeding downward in $L$. $L$ can be takensmaller than any distance practical for experiments, so the lambda model, ifright, gives all actually observable physics. The harmonic surfaces in themanifold of spacetimes are expected to have novel nonperturbative effects atlarge distances.Comment: Latex, 107 page