ﻻ يوجد ملخص باللغة العربية
The discovery of a small cosmological constant has stimulated interest in the measure problem. One should expect to be a typical observer, but defining such a thing is difficult in the vastness of an eternally inflating universe. We propose that a crucial prerequisite is understanding why one should exist as an observer at all. We assume that the Physical Church Turing Thesis is correct and therefore all observers (and everything else that exists) can be described as different types of information. We then argue that the observers collectively form the largest class of information (where, in analogy with the Faddeev Popov procedure, we only count over gauge invariant forms of information). The statistical predominance of the observers is due to their ability to selectively absorb other forms of information from many different sources. In particular, it is the combinatorics that arise from this selection process which leads us to equate the observer class $mathcal{O}$ with the nontrivial power set $hat{mathcal{P}}(mathcal{U})$ of the set of all information $mathcal{U}$. Observers themselves are thus the typical form of information. If correct, this proposal simplifies the measure problem, and leads to dramatic long term predictions.
The Thermal Time Hypotheis (TTH) has been proposed as a general method for identifying a time variable from within background-free theories which do not come equipped with a pre-defined clock variable. Here, we explore some implications of the TTH in
The Riemann Hypothesis states that the Riemann zeta function $zeta(z)$ admits a set of non-trivial zeros that are complex numbers supposed to have real part $1/2$. Their distribution on the complex plane is thought to be the key to determine the numb
We compare two approaches to Semi-Riemannian metrics of low regularity. The maximally reasonable distributional setting of Geroch and Traschen is shown to be consistently contained in the more general setting of nonlinear distributional geometry in the sense of Colombeau.
By using a method improved with a generalized optical metric, the deflection of light for an observer and source at finite distance from a lens object in a stationary, axisymmetric and asymptotically flat spacetime has been recently discussed [Ono, I
In four dimensions, the most general metric admitting two Killing vectors and a rank-two Killing tensor can be parameterized by ten arbitrary functions of a single variable. We show that picking a special vierbien, reducing the system to eight functi