Comment on the Calculation of the Angular Momentum and Mass for the (Anti-) Self Dual Charged Spinning BTZBTZ Black Hole

A recent paper [M. Kamata and T. Koikawa, Phys. Lett. {\bf B353} (1995) 196.] claimed to obtain the charged version of the $(2+1)$-dimensional spinning $BTZ$ black hole solution by assuming a (anti-) self dual condition imposed on the electric and magnetic fields. We point out that the angular momentum and mass diverge at spatial infinity and as a consequence the solution is unphysicalComment: 4 pages, Latex, no figures, final version to be publised in Phys. Lett.

Spinning Black Holes in (2+1)-dimensional String and Dilaton Gravity

We present a new class of spinning black hole solutions in $(2+1)$-dimensional general relativity minimally coupled to a dilaton with potential $e^{b\phi}\Lambda$. When $b=4$, the corresponding spinning black hole is a solution of low energy $(2+1)$-dimensional string gravity. Apart from the limiting case of the $BTZ$ black hole, these spinning black holes have no inner horizon and a curvature singularity only at the origin. We compute the mass and angular momentum parameters of the solutions at spatial infinity, as well as their temperature and entropy.Comment: 8 pages, Latex, statements about mass of 2+1 Hirschmann and Welch magnetic solution corrected, in press in Phys. Lett.

Higher Dimensional Dilaton Black Holes with Cosmological Constant

The metric of a higher-dimensional dilaton black hole in the presence of a cosmological constant is constructed. It is found that the cosmological constant is coupled to the dilaton in a non-trivial way. The dilaton potential with respect to the cosmological constant consists of three Liouville-type potentials.Comment: 8 pages,to appear in Phys. Lett.

Charged Black Cosmic String

Global U(1) strings with cylindrical symmetry are studied in anti-de Sitter spacetime. According as the magnitude of negative cosmological constant, they form regular global cosmic strings, extremal black cosmic strings and charged black cosmic strings, but no curvature singularity is involved. The relationship between the topological charge of a neutral global string and the black hole charge is clarified by duality transformation. Physical relevance as straight string is briefly discussed.Comment: ll pages, LaTe

Blockchain-based electronic voting protocol

Current electronic voting protocol require a centralized system to control the whole procedure from ballot inputs to result outputs and election monitoring. Meanwhile, blockchain technology provide a decentralized system which open across the whole network of untrusted participants. Applying blockchain technology into electronic voting protocol through a proper architecture can instil characteristic such as data confidentiality, data integrity and data authenticity. In this paper, we going to discuss a proposed method on how to leverage the advantages from blockchain into electronic voting protocol. This blockchain-based electronic voting protocol promise to provide a secure electronic election process given the proposed system works. We implement a protocol using blockchain to turn election protocol into an automated control system without relying any single point of entity. Lastly, we discuss the characteristics of our proposed blockchain-based electronic voting protocol in this paper. However, there are also emerging challenges and limitations awaiting to overcome. This paper gives a comprehensive overview of our proposed protocol

Entropy for Asymptotically AdS_3 Black Holes

We propose that Strominger's method to derive the BTZ black hole entropy is in fact applicable to other asymptotically AdS_3 black holes and gives the correct functional form of entropies. We discuss various solutions in the Einstein-Maxwell theory, dilaton gravity, Einstein-scalar theories, and Einstein-Maxwell-dilaton theory. In some cases, solutions approach AdS_3 asymptotically, but their entropies do not have the form of Cardy's formula. However, it turns out that they are actually not "asymptotically $AdS_3$" solutions. On the other hand, for truly asymptotically AdS_3 solutions, their entropies have the form of Cardy's formula. In this sense, all known solutions are consistent with our proposal.Comment: 21 pages, LaTeX; v2: added discussion for section 3.

'Deadman' and 'Passcode' microbial kill switches for bacterial containment

Biocontainment systems that couple environmental sensing with circuit-based control of cell viability could be used to prevent escape of genetically modified microbes into the environment. Here we present two engineered safeguard systems known as the 'Deadman' and 'Passcode' kill switches. The Deadman kill switch uses unbalanced reciprocal transcriptional repression to couple a specific input signal with cell survival. The Passcode kill switch uses a similar two-layered transcription design and incorporates hybrid LacI-GalR family transcription factors to provide diverse and complex environmental inputs to control circuit function. These synthetic gene circuits efficiently kill Escherichia coli and can be readily reprogrammed to change their environmental inputs, regulatory architecture and killing mechanism.United States. Defense Threat Reduction Agency (Grant HDTRA1-14-1-0006)Howard Hughes Medical InstituteUnited States. Office of Naval Research. Multidisciplinary University Research Initiative (Grant N000141110725)United States. Air Force Office of Scientific Research (Grant FA9550-14-1-0060

Rotating Dilaton Solutions in 2+1 Dimensions

We report a three parameter family of solutions for dilaton gravity in 2+1 dimensions with finite mass and finite angular momentum. These solutions are obtained by a compactification of vacuum solutions in 3+1 dimensions with cylindrical symmetry. One class of solutions corresponds to conical singularities and the other leads to curvature singularities.Comment: Accepted to be published in Gen. Rel. Grav., added reference

Bose-Einstein Condensate in Weak 3d Isotropic Speckle Disorder

The effect of a weak three-dimensional (3d) isotropic laser speckle disorder on various thermodynamic properties of a dilute Bose gas is considered at zero temperature. First, we summarize the derivation of the autocorrelation function of laser speckles in 1d and 2d following the seminal work of Goodman. The goal of this discussion is to show that a Gaussian approximation of this function, proposed in some recent papers, is inconsistent with the general background of laser speckle theory. Then we propose a possible experimental realization for an isotropic 3d laser speckle potential and derive its corresponding autocorrelation function. Using a Fourier transform of that function, we calculate both condensate depletion and sound velocity of a Bose-Einstein condensate as disorder ensemble averages of such a weak laser speckle potential within a perturbative solution of the Gross-Pitaevskii equation. By doing so, we reproduce the expression of the normalfluid density obtained earlier within the treatment of Landau. This physically transparent derivation shows that condensate particles, which are scattered by disorder, form a gas of quasiparticles which is responsible for the normalfluid component

One-by-one trap activation in silicon nanowire transistors

Flicker or 1/f noise in metal-oxide-semiconductor field-effect transistors (MOSFETs) has been identified as the main source of noise at low frequency. It often originates from an ensemble of a huge number of charges trapping and detrapping. However, a deviation from the well-known model of 1/f noise is observed for nanoscale MOSFETs and a new model is required. Here, we report the observation of one-by-one trap activation controlled by the gate voltage in a nanowire MOSFET and we propose a new low-frequency-noise theory for nanoscale FETs. We demonstrate that the Coulomb repulsion between electronically charged trap sites avoids the activation of several traps simultaneously. This effect induces a noise reduction by more than one order of magnitude. It decreases when increasing the electron density in the channel due to the electrical screening of traps. These findings are technologically useful for any FETs with a short and narrow channel.Comment: One file with paper and supplementary informatio