We introduce the concept of a quantum background and a functor QFT. In the case that the QFT moduli space is smooth formal, we construct a flat quantum superconnection on a bundle over QFT which defines algebraic structures relevant to correlation functions in quantum field theory. We go further and identify chain level generalizations of correlation functions which should be present in all qua...

The Massive Open Online Course (MOOC) has expanded significantly in recent years. With the widespread of MOOC, the opportunity to study the fascinating courses for free has attracted numerous people of diverse educational backgrounds all over the world. In the big data era, a key research topic for MOOC is how to mine the needed courses in the massive course databases in cloud for each individu...

The propagation of strings in cosmological space-time backgrounds is reviewed. We show the relation of a special class of cosmological backgrounds to exact conformal field theory. Particular emphasis is put on the singularity structure of the cosmological space-time and on the discrete duality symmetries of the string background.

We study classical supertube probes on supergravity backgrounds which are sourced by over-rotating supertubes, and which therefore contain closed timelike curves. We show that the BPS probes are stable despite the appearance of negative kinetic terms in the probe action. By studying the radial oscillations of these probes, we show that closed geodesics exist on these backgrounds. email address:...

An overview is presented of possible cosmologically distant sources of gravitational wave backgrounds, especially those which might produce detectable backgrounds in the LISA band between 0.1 and 100 mHz. Examples considered here include inflation-amplified vacuum fluctuations in inflaton and graviton fields, bubble collisions in first-order phase transitions, Goldstone modes of classical self-...

As a feature of local cultural heritage, historical garden sites should not only focus on landscape sightseeing, but also champion the sustainability heritage and promote community’s wellbeing. This article uses narrative method to explore how public, with both professional non-professional backgrounds, manages enhances its sustainability. Qing Yan Yuan is site in Huai’an, Jiangsu Province, Chi...

Improving change detection performance (probability of detection/false alarm rate) is an important goal of DARPA's Dynamic Database (DDB) program. We describe a novel approach based on fusing the outputs from two complementary image-based change detection algorithms. Both use historical imagery over the region of interest to construct normalcy models for detecting change. Image level change det...

We study giant graviton probes in the framework of the three–parameter deformation of the AdS5 × S background. We examine both the case when the brane expands in the deformed S̃ part of the geometry and the case when it blows up into AdS5. Performing a detailed analysis of small fluctuations around the giants, the configurations turn out to be stable. Our results hold even for the supersymmetric...

Here we discuss the two dimensional quantum electrodynamics in curved spacetime, especially in the background of some black holes. We first show the existence of some new quantum mechanical solution which has interesting properties. Then for some special black holes we discuss the fermion-black hole scattering problem. The issue of confinement is intimately connected with these solutions and we...

We describe a large class of exact string backgrounds with a null Killing vector arising, via a limiting à la Penrose procedure, from string backgrounds corresponding to coset conformal field theories for compact groups GN/HN times a free time-like boson U(1)−N . In this way a class of novel logarithmic conformal field theories (LCFT) emerges, that includes the one constructed recently as an N ...