5,532 research outputs found

    Kernel Code Integrity Protection Based on a Virtualized Memory Architecture

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    Kernel rootkits pose significant challenges on defensive techniques as they run at the highest privilege level along with the protection systems. Modern architectural approaches such as the NX protection have been used in mitigating attacks, however determined attackers can still bypass these defenses with specifically crafted payloads. In this paper, we propose a virtualized Harvard memory architecture to address the kernel code integrity problem, which virtually separates the code fetch and data access on the kernel code to prevent kernel from code modifications. We have implemented the proposed mechanism in commodity operating system, and the experimental results show that our approach is effective and incurs very low overhead

    Gravitational Corrections to Φ4\Phi^{4} Theory with Spontaneously Broken Symmetry

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    We consider a complex scalar Φ4\Phi^4 theory with spontaneously broken global U(1) symmetry, minimally coupling to perturbatively quantized Einstein gravity which is treated as an effective theory at the energy well below the Planck scale. Both the lowest order pure real scalar correction and the gravitational correction to the renormalization of the Higgs sector in this model have been investigated. Our results show that the gravitational correction renders the renormalization of the Higgs sector in this model inconsistent while the pure real scalar correction to it leads to a compatible renormalization.Comment: 11 pages, 24 figure

    Ionized gas outflows in infrared-bright dust-obscured galaxies selected with WISE and SDSS

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    We present the ionized gas properties of infrared (IR)-bright dust-obscured galaxies (DOGs) that show an extreme optical/IR color, (i[22])AB>7.0(i - [22])_{\rm AB} > 7.0, selected with the Sloan Digital Sky Survey (SDSS) and Wide-field Infrared Survey Explorer (WISE). For 36 IR-bright DOGs that show [OIII]λ\lambda5007 emission in the SDSS spectra, we performed a detailed spectral analysis to investigate their ionized gas properties. In particular, we measured the velocity offset (the velocity with respect to the systemic velocity measured from the stellar absorption lines) and the velocity dispersion of the [OIII] line. We found that the derived velocity offset and dispersion of most IR-bright DOGs are larger than those of Seyfert 2 galaxies (Sy2s) at z<0.3z < 0.3, meaning that the IR-bright DOGs show relatively strong outflows compared to Sy2s. This can be explained by the difference of IR luminosity contributed from active galactic nucleus, LIRL_{\rm IR} (AGN), because we found that (i) LIRL_{\rm IR} (AGN) correlates with the velocity offset and dispersion of [OIII] and (ii) our IR-bright DOGs sample has larger LIRL_{\rm IR} (AGN) than Sy2s. Nevertheless, the fact that about 75% IR-bright DOGs have a large (>> 300 km s1^{-1}) velocity dispersion, which is a larger fraction compared to other AGN populations, suggests that IR-bright DOGs are good laboratories to investigate AGN feedback. The velocity offset and dispersion of [OIII] and [NeIII]λ\lambda3869 are larger than those of [OII]λ\lambda3727, which indicates that the highly ionized gas tends to show more stronger outflows.Comment: 19 pages, 16 figures, and 2 tables, accepted for publication in Ap
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