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The challenge of taking many variables into account in optimization problems may be overcome under the hypothesis of low effective dimensionality. Then, the search of solutions can be reduced to the random embedding of a low dimensional…

Optimization and Control · Mathematics 2018-10-23 Mickaël Binois , David Ginsbourger , Olivier Roustant

In this article the cosmological constant problems, as well as the astronomical evidence for a cosmologically significant homogeneous exotic energy density with negative pressure (quintessence), are reviewed for a broad audience of…

Astrophysics · Physics 2007-05-23 Norbert Straumann

We investigate the physically accepted solutions of general Braneworld scenarios, scanning uniformly the associated parameter space. Without making any further assumptions we find that solutions which give "small" Hubble parameters on the…

High Energy Physics - Theory · Physics 2009-03-27 F. K. Diakonos , E. N. Saridakis

Until now, Computer Scientists have concerned themselves with identifying efficient algorithms for solving the general case of some problem -- that is finding one which performs well when the size of the input tends to infinity. In this…

Computational Complexity · Computer Science 2026-04-21 Mircea-Adrian Digulescu

The observed value of the cosmological constant poses large theoretical problems. We find that topology of the Universe provides a natural source for it. Restricting dynamically an Einstein-Cartan gravity to General Relativity in our…

General Relativity and Quantum Cosmology · Physics 2020-06-16 M. Le Delliou , J. Lorca Espiro

According to general relativity, the present analysis shows on geometrical grounds that the cosmological constant problem is an artifact due to the unfounded link of this fundamental constant to vacuum energy density of quantum…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Roland Triay

The cosmological constant problem arises because the magnitude of vacuum energy density predicted by quantum mechanics is about 120 orders of magnitude larger than the value implied by cosmological observations of accelerating cosmic…

General Relativity and Quantum Cosmology · Physics 2018-09-19 Samuel S. Cree , Tamara M. Davis , Timothy C. Ralph , Qingdi Wang , Zhen Zhu , William G. Unruh

The old cosmological constant problem is to understand why the vacuum energy is so small; the new problem is to understand why it is comparable to the present mass density. Several approaches to these problems are reviewed. Quintessence…

Astrophysics · Physics 2007-05-23 Steven Weinberg

The cosmological constant problem is explained by a theory based on the discrete space-time hypothesis. The calculated cosmological constant value is of the order of 10^-52[m]^-2 or equivalent to about 0.7 of the critical mass density. It…

Astrophysics · Physics 2007-05-23 H. M. Mok

Optimisation problems are ubiquitous in particle and astrophysics, and involve locating the optimum of a complicated function of many parameters that may be computationally expensive to evaluate. We describe a number of global optimisation…

One often hears that the strong $CP$ problem is the one problem which cannot be solved by anthropic reasoning. We argue that this is not so. Due to nonperturbative dynamics, states with a different $CP$ violating paramenter $\theta$ acquire…

High Energy Physics - Theory · Physics 2017-12-11 Nemanja Kaloper , John Terning

We are given n base elements and a finite collection of subsets of them. The size of any subset varies between p to k (p < k). In addition, we assume that the input contains all possible subsets of size p. Our objective is to find a…

Data Structures and Algorithms · Computer Science 2009-06-09 Asaf Levin , Uri Yovel

We present a broad and simple class of scalar-tensor scenarios that successfully realize dynamical damping of the effective cosmological constant, therefore providing a viable dynamical solution to the fine-tuning or "old" cosmological…

General Relativity and Quantum Cosmology · Physics 2018-12-27 Oleg Evnin , Kévin Nguyen

The discovery that the expansion of the universe is accelerating in time is a major discovery which still awaits adequate explanation. It is generally agreed that this implies a cosmic repulsion as a result of the existence of a…

General Physics · Physics 2008-11-26 R. F. O'Connell

Variational quantum algorithms are proposed to solve relevant computational problems on near term quantum devices. Popular versions are variational quantum eigensolvers and quantum ap- proximate optimization algorithms that solve ground…

Quantum Physics · Physics 2022-04-15 Lennart Bittel , Martin Kliesch

Faced by recent evidence for a flat universe dominated by dark energy, cosmologists grapple with deep cosmic enigmas such as the cosmological constant problem, extreme fine-tuning and the cosmic coincidence problem. The extent to which we…

Astrophysics · Physics 2016-08-30 Greg Huey , Benjamin D. Wandelt

State-of-the-art quantum algorithms routinely tune dynamically parametrized cost functionals for combinatorics, machine learning, equation-solving, or energy minimization. However, large search complexity often demands many (noisy) quantum…

Quantum Physics · Physics 2022-01-12 Mogens Dalgaard , Felix Motzoi , Jacob Sherson

We consider the following generalization of binary search in sorted arrays to tree domains. In each step of the search, an algorithm is querying a vertex $q$, and as a reply, it receives an answer, which either states that $q$ is the…

Data Structures and Algorithms · Computer Science 2024-01-26 Dariusz Dereniowski , Izajasz Wrosz

In this article we use the idea of algorithmic complexity (AC) to study various cosmological scenarios, and as a means of quantizing the gravitational interaction. We look at 5D and 7D cosmological models where the Universe begins as a…

General Relativity and Quantum Cosmology · Physics 2015-06-25 V. Dzhunushaliev , D. Singleton

There appears to be no natural explanation for the cosmological constant's small size within the framework of local relativistic field theories. We argue that the recently-discussed framework for which the observable universe is identified…

High Energy Physics - Theory · Physics 2009-10-31 C. P. Burgess , R. C. Myers , F. Quevedo