16 research outputs found

    Phase Structure of Four-dimensional Simplicial Quantum Gravity with a U(1) Gauge Field

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    The phase structure of four-dimensional simplicial quantum gravity coupled to U(1) gauge fields has been studied using Monte-Carlo simulations. The smooth phase is found in the intermediate region between the crumpled phase and the branched polymer phase. This new phase has a negative string susceptibility exponent, even if the number of vector fields (Nv) is 1. The phase transition between the crumpled phase and the smooth phase has been studied by a finite size scaling method. From the numerical results, we expect that this model (coupled to one gauge field) has a higher order phase transition than first order, which means the possibility to take the continuum limit at the critical point. Furthermore, we consider a modification of the balls-in-boxes model for a clear understanding of the relation between the numerical results and the analytical one.Comment: 18 pages, latex, 6 figures, uses psfig.st

    Analyzing WMAP Observation by Quantum Gravity

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    The angular power spectra of cosmic microwave background are analyzed under the light of the evolutional scenario of the universe based on the renormalizable quantum theory of gravity in four dimensions. The equation of evolution is solved numerically fixing the power law spectrum predicted by the conformal gravity for the initial condition. The equation requires to introduce a dynamical energy scale about 10^{17}GeV, where the inflationary space-time evolution makes a transition to the big-bang of the conventional Friedmann universe. The quality of fit to the three-year data of WMAP implies the possibility to understand the observation by quantum gravity.Comment: 12 pages, 7 figure

    Discrete space formulation of quantum geometry on R × Sd-1

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    A numerical formulation of d-dimensional quantum gravity on R × Sd−1 is developed based on the d-dimensional dynamical triangulation method. It provides tools to analyze space-time properties of the (d − 1)-dimensional space with sphere topology along the direction R, in which time coordinate can be defined naturally. As examples, we show numerical results of the 2-dimensional (R × S) model, and compare with the matrix model. Furthermore, we measure the 2-space point correlation function on the last scattering surface of 3-dimensional space S3, and compare it to the CMB anisotropy observation results of COBE and WMAP. The numerical simulation exhibits the inflation without any additional fields, and the quantized space-time possesses properties required from observations

    Developing Deception Network System with Traceback Honeypot in ICS Network

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    In industrial control system (ICS) network, communication is often conducted using custom protocols. Methods for analysis and protection from cyber threats that are specific to ICS network need to be discussed in line with each device and system specification. In this research, the honeypot technology, which is already practiced in IT networks, was further improved for ICS networks so that it responds to packets reaching the honeypots and even conducts counter-scan to collect information of the attack method and its sources. It has been already presented that machines infected with some known malware (e.g. Havex RAT) in ICS networks conduct scan activities against certain devices. For this type of attack, interaction honeypot is considered effective in identifying infected devices out of such scans. In the simulation based on Modbus Stager, which affects programmable logic controller (PLC) operation and connected PCs, the suggested interaction honeypot, namely “traceback honeypot system (THS)” successfully collected payload that is actually sent in the attacks by emulating responses to commands on Modbus protocols. Information obtained from THS-based observation can be used for proactive purposes as in separating infected devices from the operating network and restricting access to certain devices to prevent further infection in the ICS network. This paper discusses methods of tracking attack sources using the THS and preventing further infection within the network based on the search result

    Numerical analysis of the double scaling limit in the string type IIB matrix model

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    The bosonic IIB matrix model is studied using a numerical method. This model contains the bosonic part of the IIB matrix model conjectured to be a nonperturbative definition of the type IIB superstring theory. The large N scaling behavior of the model is shown performing a Monte Carlo simulation. The expectation value of the Wilson loop operator is measured and the string tension is estimated. The numerical results show the prescription of the double scaling limit
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