2005 - otherworldlines

# Aharony, Minwalla, Wiseman ## Plasma-balls in large N gauge theories and localized black holes \[Links: [arXiv](https://arxiv.org/abs/hep-th/0507219), [PDF](https://arxiv.org/pdf/hep-th/0507219.pdf)\] \[Abstract: We argue for the existence of plasma-balls - meta-stable, nearly homogeneous lumps of gluon plasma at just above the deconfinement energy density - in a class of large N confining gauge theories that undergo first order deconfinement transitions. Plasma-balls decay over a time scale of order N^2 by thermally radiating hadrons at the deconfinement temperature. In gauge theories that have a dual description that is well approximated by a theory of gravity in a warped geometry, we propose that plasma-balls map to a family of classically stable finite energy black holes localized in the IR. We present a conjecture for the qualitative nature of large mass black holes in such backgrounds, and numerically construct these black holes in a particular class of warped geometries. These black holes have novel properties; in particular their temperature approaches a nonzero constant value at large mass. Black holes dual to plasma-balls shrink as they decay by Hawking radiation; towards the end of this process they resemble ten dimensional Schwarzschild black holes, which we propose are dual to small plasma-balls. Our work may find practical applications in the study of the physics of localized black holes from a dual viewpoint.\] ## Extracts Precisely at the deconfinement temperature, the period of the Euclidean time circle and that of the Scherk–Schwarz circle become equal. Moreover, at this critical temperature the pressure of the plasma vanishes. This suggests that there might exist a solution of the Einstein equations in the bulk which interpolates between the AdS soliton geometry (confined phase) and the planar Schwarzschild–AdS black hole (deconfined phase). This expectation turns out to be correct and Ref. [8] constructed, numerically, such a solution. The existence of such a domain wall solution led the authors of [8] to conjecture that finite size black holes, localized at the IR bottom of the AdS-soliton background, should also exist. From the dual CFT perspective, these black holes would correspond to finite size balls of deconfined plasma surrounded by the confining vacuum. In fact, [8] argued that finite size plasma balls should generically exist in any confining large Nc gauge theory that exhibits a first order confinement/deconfinement phase transition. In the semiclassical approximation, such plasma balls should be stable. The reason is that in the full quantum theory, plasma balls in confining backgrounds can only evaporate via the emission of colour singlet glueball states. This process is the dual of the Hawking evaporation in the bulk. However, out of the O(N2 c ) degrees of freedom available in the theory, only O(1) correspond to the colour singlet states that can be emitted into the confining vacuum. Therefore, the evaporation process of the plasma balls is suppressed in the large Nc limit [8]. # Banados, Olea, Theisen ## Counterterms and dual holographic anomalies in CS gravity \[Links: [arXiv](https://arxiv.org/abs/hep-th/0509179), [PDF](https://arxiv.org/pdf/hep-th/0509179.pdf)\] \[Abstract: The [[0209 Holographic renormalisation|holographic Weyl anomaly]] associated to Chern-Simons gravity in 2n+1 dimensions is proportional to the Euler term in $2n$ dimensions, with no contributions from the Weyl tensor. We compute the holographic energy-momentum tensor associated to [[0089 Chern-Simons theory|Chern-Simons gravity]] directly from the action, in an arbitrary odd-dimensional spacetime. We show, in particular, that the counterterms rendering the action finite contain only terms of the [[0341 Lovelock gravity|Lovelock]] type.\] ## Summary - finds that [[0209 Holographic renormalisation|holographic anomaly]] for 2n+1 dimensional [[0089 Chern-Simons theory|CS theory]] is proportional to Euler density and has no contribution from the [[0306 Weyl anomaly|Weyl tensor]] - CT only involves [[0341 Lovelock gravity|Lovelock type]] terms # Beasley, Witten ## Non-Abelian Localization For Chern-Simons Theory \[Links: [arXiv](https://arxiv.org/abs/hep-th/0503126), [PDF](https://arxiv.org/pdf/hep-th/0503126.pdf)\] \[Abstract: We reconsider [[0089 Chern-Simons theory|Chern-Simons gauge theory]] on a Seifert manifold $M$ (the total space of a nontrivial circle bundle over a Riemann surface). When $M$ is a Seifert manifold, Lawrence and Rozansky have shown from the exact solution of Chern-Simons theory that the partition function has a remarkably simple structure and can be rewritten entirely as a sum of local contributions from the flat connections on $M$. We explain how this empirical fact follows from the technique of non-abelian localization as applied to the Chern-Simons path integral. In the process, we show that the partition function of Chern-Simons theory on $M$ admits a topological interpretation in terms of the equivariant cohomology of the moduli space of flat connections on $M$.\] # Birthwright, Glover, Khoze, Marquard (Mar) ## Multi-gluon collinear limits from MHV diagrams \[Links: [arXiv](https://arxiv.org/abs/hep-ph/0503063), [PDF](https://arxiv.org/pdf/hep-ph/0503063.pdf)\] \[Abstract: \] ## Summary - ==tree-level== collinear limits of up to six ==gluons== - derive timelike splitting functions - valid for specific numbers of negative helicity gluons and arbitrary number of positive helicity gluons - used in project [[asymp_multicol]] ## Why it works - [[0352 CSW relations|MHV rules]] imply that in the collinear limit, the full amplitude factorises into an MHV vertex multiplied by a multi-collinear splitting function (that depends on the helicities of the collinear gluons) - the full amplitude not needed: only a subset contributes - only MHV diagrams which contain an internal propagator that goes on-shell in the multi-collinear limit - i.e. the IR singularities in the MHV approach arise solely from on-shell internal propagators - warning: not true in the [[0058 BCFW]] approach ## Set up ![[BirthwrightGloverKhozeMarquard200503_ncolli.png]] ## Extensions - [[BirthwrightGloverKhozeMarquard200505]] - (by the same authors) - applied to QCD (massless quarks added) - (Atul) the breakthrough that allows this paper to compute gluon collinear limits is a recursion relation called [[0352 CSW relations]] . - no such recursion relations for gravitons # Britto, Cachazo, Feng, Witten ## Direct Proof Of Tree-Level Recursion Relation In Yang-Mills Theory \[Links: [arXiv](https://arxiv.org/abs/hep-th/0501052), [PDF](https://arxiv.org/pdf/hep-th/0501052.pdf)\] \[Abstract: Recently, by using the known structure of one-loop scattering amplitudes for gluons in Yang-Mills theory, a [[0551 On-shell recursion relations|recursion relation]] for tree-level scattering amplitudes has been deduced. Here, we give a short and direct proof of this recursion relation based on properties of tree-level amplitudes only.\] ## Refs - [[0058 BCFW]] - [[0551 On-shell recursion relations]] # Cachazo, Svrcek (Lecture) ## Lectures on Twistor Strings and Perturbative Yang-Mills Theory \[Links: [arXiv](https://arxiv.org/abs/hep-th/0504194), [PDF](https://arxiv.org/pdf/hep-th/0504194.pdf)\] \[Abstract: Recently, Witten proposed a topological string theory in [[0330 Twistor theory|twistor space]] that is dual to a weakly coupled gauge theory. In this lectures we will discuss aspects of the [[0497 Twistor string theory|twistor string theory]]. Along the way we will learn new things about [[0071 Yang-Mills|Yang-Mills]] scattering amplitudes. The string theory sheds light on Yang-Mills perturbation theory and leads to new methods for computing Yang-Mills scattering amplitudes.\] # Calabrese, Cardy ## Evolution of Entanglement Entropy in One-Dimensional Systems \[Links: [arXiv](https://arxiv.org/abs/cond-mat/0503393), [PDF](https://arxiv.org/pdf/cond-mat/0503393.pdf)\] \[Abstract: We study the unitary time evolution of the [[0301 Entanglement entropy|entropy of entanglement]] of a one-dimensional system between the degrees of freedom in an interval of length $l$ and its complement, starting from a pure state which is not an eigenstate of the hamiltonian. We use ==path integral methods of quantum field theory== as well as explicit computations for the ==transverse Ising spin chain==. In both cases, there is a maximum speed $v$ of propagation of signals. In general the entanglement entropy increases linearly with time t up to $t=l/2v$, after which it saturates at a value proportional to $l$, the coefficient depending on the initial state. This behavior may be understood as a consequence of causality.\] ## Comments - the computation here is done in Euclidean signature and then analytically continued ## Refs - this paper contains important early work on [[0522 Entanglement dynamics|entanglement dynamics]] - [[2007#Calabrese, Cardy (Apr)]] ## Results The entanglement entropy of an interval (of length $l$) in 1+1 CFT after a uniform [[0558 Quantum quench|quench]]:$S_R(t)-S_R(t=0)= \begin{cases}2 s_{\mathrm{th}} t & t<\ell / 2 \\ s_{\mathrm{th}} \ell & t \geq \ell / 2\end{cases}$ # Fjelstad, Fuchs, Runkel, Schweigert ## TFT construction of RCFT correlators V: Proof of modular invariance and factorisation \[Links: [arXiv](https://arxiv.org/abs/hep-th/0503194), [PDF](https://arxiv.org/pdf/hep-th/0503194)\] \[Abstract: The correlators of two-dimensional rational conformal field theories that are obtained in the TFT construction of \[FRSI,FRSII,FRSIV\] are shown to be invariant under the action of the relative modular group and to obey bulk and boundary factorisation constraints. We present results both for conformal field theories defined on oriented surfaces and for theories defined on unoriented surfaces. In the latter case, in particular the so-called cross cap constraint is included.\] # Giddings, Marolf, Hartle ## Observables in effective gravity \[Links: [arXiv](https://arxiv.org/abs/hep-th/0512200), [PDF](https://arxiv.org/pdf/hep-th/0512200)\] \[Abstract: We address the construction and interpretation of diffeomorphism-invariant observables in a low-energy effective theory of quantum gravity. The observables we consider are constructed as integrals over the space of coordinates, in analogy to the construction of gauge-invariant observables in Yang-Mills theory via traces. As such, they are explicitly non-local. Nevertheless we describe how, in suitable quantum states and in a suitable limit, the familiar physics of local quantum field theory can be recovered from appropriate such observables, which we term 'pseudo-local.' We consider measurement of pseudo-local observables, and describe how such measurements are limited by both quantum effects and gravitational interactions. These limitations support suggestions that theories of quantum gravity associated with finite regions of spacetime contain far fewer degrees of freedom than do local field theories.\] # Godina, Matteucci ## The Lie derivative of spinor fields: theory and applications \[Links: [arXiv](https://arxiv.org/abs/math/0504366), [PDF](https://arxiv.org/pdf/math/0504366.pdf)\] \[Abstract: Starting from the general concept of a Lie derivative of an arbitrary differentiable map, we develop a systematic theory of Lie differentiation in the framework of reductive $G$-structures $P$ on a principal bundle $Q$. It is shown that these structures admit a canonical decomposition of the pull-back vector bundle $i_P^*(TQ) = P\times_Q TQ$ over $P$. For classical $G$-structures, i.e. reductive $G$-subbundles of the linear frame bundle, such a decomposition defines an infinitesimal canonical lift. This lift extends to a prolongation Gamma-structure on $P$. In this general geometric framework the concept of a Lie derivative of spinor fields is reviewed. On specializing to the case of the Kosmann lift, we recover Kosmann's original definition. We also show that in the case of a reductive $G$-structure one can introduce a "reductive Lie derivative" with respect to a certain class of generalized infinitesimal automorphisms, and, as an interesting by-product, prove a result due to Bourguignon and Gauduchon in a more general manner. Next, we give a new characterization as well as a generalization of the Killing equation, and propose a geometric reinterpretation of Penrose's Lie derivative of "spinor fields". Finally, we present an important application of the theory of the Lie derivative of spinor fields to the calculus of variations.\] # Griffiths, Podolsky ## A new look at the Plebanski-Demianski family of solutions \[Links: [arXiv](https://arxiv.org/abs/gr-qc/0511091), [PDF](https://arxiv.org/pdf/gr-qc/0511091.pdf)\] \[Abstract: The Plebanski-Demianski metric, and those that can be obtained from it by taking coordinate transformations in certain limits, include the complete family of space-times of type D with an aligned electromagnetic field and a possibly non-zero cosmological constant. Starting with a new form of the line element which is better suited both for physical interpretation and for identifying different subfamilies, we review this entire family of solutions. Our metric for the expanding case explicitly includes two parameters which represent the acceleration of the sources and the twist of the repeated principal null congruences, the twist being directly related to both the angular velocity of the sources and their NUT-like properties. The non-expanding type D solutions are also identified. All special cases are derived in a simple and transparent way.\] # Hollands, Ishibashi, Marolf ## Counter-term charges generate bulk symmetries \[Links: [arXiv](https://arxiv.org/abs/hep-th/0503105), [PDF](https://arxiv.org/pdf/hep-th/0503105.pdf)\] \[Abstract: \] # Horowitz ## Tachyon condensation and black strings \[Links: [arXiv](https://arxiv.org/abs/hep-th/0506166), [PDF](https://arxiv.org/pdf/hep-th/0506166.pdf)\] \[Abstract: We show that under certain conditions, closed string tachyon condensation produces a topology changing transition from black strings to Kaluza-Klein “[[0168 Bubble of nothing|bubbles of nothing]].” This can occur when the curvature at the horizon is much smaller than the string scale, so the black string is far from the correspondence point when it would make a transition to an excited fundamental string. This provides a dramatic new endpoint to [[0304 Hawking radiation|Hawking evaporation]]. A similar transition occurs for black $p$-branes, and can be viewed as a nonextremal version of a geometric transition. Applications to AdS black holes and the AdS soliton are also discussed.\] ## Summary - tachyon condensation produces a transition from black string to [[0168 Bubble of nothing|bubble of nothing]] - focus on the case that the circle reaches string size *outside* of the horizon # Kitaev, Preskill ## Topological entanglement entropy \[Links: [arXiv](https://arxiv.org/abs/hep-th/0510092), [PDF](https://arxiv.org/pdf/hep-th/0510092.pdf)\] \[Abstract: We formulate a universal characterization of the many-particle quantum entanglement in the ground state of a [[0158 Topological order|topologically ordered]] ==two-dimensional medium with a mass gap==. We consider a disk in the plane, with a smooth boundary of length $L$, large compared to the correlation length. In the ground state, by tracing out all degrees of freedom in the exterior of the disk, we obtain a marginal density operator $\rho$ for the degrees of freedom in the interior. The [[0301 Entanglement entropy|von Neumann entropy]] $S(\rho)$ of this density operator, a measure of the entanglement of the interior and exterior variables, has the form $S(\rho)= \alpha L -\gamma + \dots$, where the ellipsis represents terms that vanish in the limit $L\to\infty$. The coefficient $\alpha$, arising from short wavelength modes localized near the boundary, is nonuniversal and ultraviolet divergent, but $-\gamma$ is a universal additive constant characterizing a global feature of the entanglement in the ground state. Using topological quantum field theory methods, we derive a formula for $\gamma$ in terms of properties of the superselection sectors of the medium.\] ## Refs - same time: [[2005#Levin, Wen]] # Kovtun, Starinets ## Quasinormal modes and holography \[Links: [arXiv](https://arxiv.org/abs/hep-th/0506184), [PDF](https://arxiv.org/pdf/hep-th/0506184.pdf)\] \[Abstract: Quasinormal frequencies of electromagnetic and gravitational perturbations in asymptotically AdS spacetime can be identified with poles of the corresponding real-time Green's functions in a holographically dual finite temperature field theory. The quasinormal modes are defined for gauge-invariant quantities which obey incoming-wave boundary condition at the horizon and Dirichlet condition at the boundary. As an application, we explicitly find poles of retarded correlation functions of R-symmetry currents and the energy-momentum tensor in strongly coupled finite temperature $N=4$ supersymmetric $SU(N_c)$ Yang-Mills theory in the limit of large $N_c$.\] # Lauda, Pfeiffer ## Open-closed strings: Two-dimensional extended TQFTs and Frobenius algebras \[Links: [arXiv](https://arxiv.org/abs/math/0510664), [PDF](https://arxiv.org/pdf/math/0510664)\] \[Abstract: We study a special sort of 2-dimensional [[0623 Extended TQFT|extended Topological Quantum Field Theories]] (TQFTs) which we call [[0625 Open-closed TQFT|open-closed TQFTs]]. These are defined on open-closed cobordisms by which we mean smooth compact oriented 2-manifolds with corners that have a particular global structure in order to model the smooth topology of open and closed string worldsheets. We show that the category of open-closed TQFTs is equivalent to the category of knowledgeable Frobenius algebras. A knowledgeable Frobenius algebra $(A,C,i,i^*)$ consists of a symmetric Frobenius algebra $A$, a commutative Frobenius algebra $C$, and an algebra homomorphism $i:C\to A$ with dual $i^*:A\to C$, subject to some conditions. This result is achieved by providing a generators and relations description of the category of open-closed cobordisms. In order to prove the sufficiency of our relations, we provide a normal form for such cobordisms which is characterized by topological invariants. Starting from an arbitrary such cobordism, we construct a sequence of moves (generalized handle slides and handle cancellations) which transforms the given cobordism into the normal form. Using the generators and relations description of the category of open-closed cobordisms, we show that it is equivalent to the symmetric monoidal category freely generated by a knowledgeable Frobenius algebra. Our formalism is then generalized to the context of open-closed cobordisms with labeled free boundary components, i.e. to open-closed string worldsheets with D-brane labels at their free boundaries.\] # Levin, Wen ## Detecting topological order in a ground state wave function \[Links: [arXiv](https://arxiv.org/abs/cond-mat/0510613), [PDF](https://arxiv.org/pdf/cond-mat/0510613.pdf)\] \[Abstract: A large class of [[0158 Topological order|topological orders]] can be understood and classified using the string-net condensation picture. These topological orders can be characterized by a set of data $(N, d_i, F^{ijk}_{lmn}, \delta_{ijk})$. We describe a way to detect this kind of [[0158 Topological order|topological order]] using only the ground state wave function. The method involves computing a quantity called the "topological entropy" which directly measures the quantum dimension $D = \sum_i d^2_i$.\] # Mann, Marolf ## Holographic renormalization of asymptotically flat spacetimes \[Links: [arXiv](https://arxiv.org/abs/hep-th/0511096), [PDF](https://arxiv.org/pdf/hep-th/0511096.pdf)\] \[Abstract: \] ## Summary - [[0209 Holographic renormalisation]] for gravity in dimension $d\ge4$ - CT is a local algebraic function of the boundary metric and Ricci scalar - unlike the background subtraction method - solutions of the renormalised action is stationary for *all* variations with fixed BC - not just e.g. ones with compact support ## Refs - follow up [[MannMarolfVirmani2006]] ## A problem There is still log divergence, but fixed by [[CompereDehouck2011]] by changing the action.  # Teschner ## An analog of a modular functor from quantized Teichmüller theory \[Links: [arXiv](https://arxiv.org/abs/math/0510174), [PDF](https://arxiv.org/pdf/math/0510174.pdf)\] \[Abstract: It is shown that the quantized Teichmüller spaces have factorization properties like those required in the definition of a modular functor.\] # Yoshino, Shiromizu, Shibata ## Close-limit analysis for head-on collision of two black holes in higher dimensions: Brill-Lindquist initial data \[Links: [arXiv](https://arxiv.org/abs/gr-qc/0508063), [PDF](https://arxiv.org/pdf/gr-qc/0508063.pdf)\] \[Abstract: Motivated by the TeV-scale gravity scenarios, we study gravitational radiation in the head-on collision of two black holes in higher dimensional spacetimes using a close-limit approximation. We prepare time-symmetric initial data sets for two black holes (the so-called [[0285 Brill-Lindquist initial data|Brill-Lindquist initial data]]) and numerically evolve the spacetime in terms of a gauge invariant formulation for the perturbation around the higher-dimensional Schwarzschild black holes. The waveform and radiated energy of gravitational waves emitted in the head-on collision are clarified. Also, the complex frequencies of fundamental [[0325 Quasi-normal modes|quasinormal modes]] of higher-dimensional Schwarzschild black holes, which have not been accurately derived so far, are determined.\] ## Critical values for the common horizon ![[YoshinoShiromizuShibata2005_tab1.png]]