Wormhole calculus, replicas, and entropies

We investigate contributions of spacetime wormholes, describing baby universe emission and absorption, to calculations of entropies and correlation functions, for example those based on the replica method. We find that the rules of the “wormhole calculus”, developed in the 1980s, together with standard quantum mechanical prescriptions for computing entropies and correlators, imply definite rules for limited patterns of connection between replica factors in simple calculations. These results stand in contrast with assumptions that all topologies connecting replicas should be summed over, and call into question the explanation for the latter. In a “free” approximation baby universes introduce probability distributions for coupling constants, and we review and extend arguments that successive experiments in a “parent” universe increasingly precisely fix such couplings, resulting in ultimately pure evolution. Once this has happened, the nontrivial question remains of how topology-changing effects can modify the standard description of black hole information loss.

Spin structures and baby universes

We extend a 2d topological model of the gravitational path integral to include sums over spin structure, corresponding to Neveu-Schwarz (NS) or Ramond (R) boundary conditions for fermions. This path integral corresponds to a correlator of boundary creation operators on a non-trivial baby universe Hilbert space, and vanishes when the number of R boundaries is odd. This vanishing implies a non-factorization of the correlator, which necessitates a dual interpretation of the bulk path integral in terms of a product of partition functions (associated to NS boundaries) and Witten indices (associated to R boundaries), averaged over an ensemble of theories with varying Hilbert space dimension and different numbers of bosonic and fermionic states. We also consider a model with End-of-the-World (EOW) branes, for which the dual ensemble then includes a sum over randomly chosen fermionic and bosonic states. We propose two modifications of the bulk path integral which restore an interpretation in a single dual theory: (i) a geometric prescription where we add extra boundaries with a sum over their spin structures, and (ii) an algebraic prescription involving “spacetime D-branes”. We extend our ideas to Jackiw-Teitelboim gravity, and propose a dual description of a single unitary theory with spin structure in a system with eigenbranes.

Gamma and Beta Model of Growing and Rotating Planck Ball

With reference to Planck scale, Mach’s relation, increasing support for large scale cosmic anisotropy and preferred directions and by introducing two new parameters Gamma and Beta, right from the beginning of Planck scale, we make an attempt to estimate ordinary matter density ratio, dark matter density ratio, mass, radius, temperature, age and expansion velocity (from and about the baby universe in all directions). We would like suggest that, from the beginning of Planck scale, 1) Dark matter can be considered as a kind of cosmic foam responsible for formation of galaxies. 2) Cosmic angular velocity is directly proportional to squared cosmic temperature. 3) Ratio of critical temperature to actual temperature plays a heuristic role in understanding ordinary and dark matter density ratios. 4) Cosmic expansion velocity increases with decreasing total matter density ratio. 5) There is no need to consider dark energy for understanding cosmic acceleration.

On the Eternal Role of Planck Scale in Machian Cosmology

Considering Planck mass as a representation of baby universe and evolving universe as a growing Planck ball, a heuristic model of quantum cosmology can be developed. By considering the famous relation GM = c2R, a Machian model of evolving quantum cosmology can also be developed with increasing matter content and decreasing matter density. In all directions, ‘from and about’ the baby universe, cosmic expansion velocity can be shown to be increasing with decreasing matter density. Estimated current cosmic mass, radius, matter density, expansion velocity and age are: 4.3352×1053 kg, 3.207×1026 m, 3.318×10-27 kg.m-3, 2.43c and 19.78 Billion respectively. As a peculiar case, considering the equality of current Hubble parameter and current angular velocity, current cosmic rotational kinetic energy can be shown to be 0.667 times the current critical energy! Proceeding further, with reference to Planck scale, cosmic temperature seems to be redshifted by a factor( ( Z T ) t + 1 ) ≅ 1 + ln ( H p l / H t ) ; where (Hpl, Ht) represent Planck scale and time dependent Hubble parameters respectively.

On the Eternal Role of Planck Scale in Machian Cosmology

Considering Planck mass as a baby universe and evolving universe as a growing Planck ball, a hypothetical spherical model of cosmology can be developed. In addition, by considering the famous relation GM = c2R, a Machian model of quantum cosmology can also be developed. Proceeding further, in all directions, cosmic expansion velocity can be referred to ‘from and about’ the baby universe. This hypothetical scenario can be made versatile by adding a heuristic idea: apart from normal expansion, ‘cosmic temperature seems to be redshifted by a factor ( ( Z T ) t + 1 ) ≅ 1 + ln ( H p l / H t ) ; where (Hpl, Ht) represent Planck scale and time dependent Hubble parameters respectively.

Classical conformality in the Standard Model from Coleman’s theory

The classical conformality (CC) is one of the possible candidates for explaining the gauge hierarchy of the Standard Model (SM). We show that it is naturally obtained from the Coleman’s theory on baby universe.