Narrow Results

We compute the boundary stress-energies of time-dependent asymptotically AdS spacetimes in five and seven dimensions, and find that their traces are equal to the respective four- and six-dimensional field-theoretic trace anomalies. This provides good supporting evidence in favor of the AdS/CFT correspondence in time-dependent backgrounds.

The stress–tensor of a massless scalar field satisfying Robin boundary conditions on two one-dimensional wall in two-dimensional Schwarzschild background is calculated. We show that vacuum expectation value of stress–tensor can be obtained explicitly by Casimir effect, trace anomaly and Hawking radiation.

Polyakov loops $L_a(T)$, $a=3,8,\dots$ are shown to give the most important non-perturbative (np) contribution to the thermodynamic potentials. Derived from the gluonic field correlators (FCs), they enter as factors into free energy. It is shown in the SU(3) case that $L_a(T)$ define to a large extent the behavior of the free energy and the trace anomaly $I(T)$, most sensitive to np effects.

The trace anomaly of conformal matter implies the existence of massless scalar poles in physical amplitudes involving the stress-energy tensor. These poles may be described by a local effective action with massless scalar fields, which couple to classical sources, contribute to gravitational scattering processes, and can have long range gravitational effects at macroscopic scales. In an effective field theory approach, the effective action of the anomaly is an infrared relevant term that should be added to the Einstein-Hilbert action of classical General Relativity to take account of macroscopic quantum effects. The additional scalar degrees of freedom contained in this effective action may be understood as responsible for both the Casimir effect in flat spacetime and large quantum backreaction effects at the horizon scale of cosmological spacetimes. These effects of the trace anomaly imply that the cosmological vacuum energy is dynamical, and its value depends on macroscopic boundary conditions at the cosmological horizon scale, rather than sensitivity to the extreme ultraviolet Planck scale.

Within the framework of the recently proposed Taylor–Lagrange regularization scheme which leads to finite elementary amplitudes in four-dimensional space–time with no additional dimensionful scales — we show that the trace of the energy–momentum tensor does not show any anomalous contribution even though quantum corrections are considered. Moreover, since the only renormalization we can think of within this scheme is a finite renormalization of the bare parameters to give the physical ones, the canonical dimension of quantum fields is also preserved by the use of this regularization scheme.

The Large Hadron Collider (LHC) at CERN has a plan to have Oxygen–Oxygen (O+O) collisions at $\sqrt{s_{\mathrm{\text{NN}}}}=7$TeV collision energy in the forthcoming run. As the system size of $\mathrm{\text{O+O}}$ collisions has the final state multiplicity overlap with those produced in PbPb, p+Pb, and pp collisions, it becomes exciting to study thermodynamic quantities using the Color String Percolation Model (CSPM). The thermodynamic quantities like temperature, shear viscosity to entropy density ratio, and trace anomaly are obtained from the soft region of the transverse momentum spectra of O+O collisions at $\sqrt{s_{\mathrm{\text{NN}}}}=7$TeV. The percolation approach within CSPM can be successfully used to describe the initial stages in high-energy heavy ion collisions in the soft region in high-energy heavy ion collisions. The obtained results for O+O collisions are compared with the published results from pp and AA collisions using ALICE data.

I will discuss how an unexpected form of trace anomaly can be obtained from holographic models with no simple string interpretation. In addition to the usual trace anomaly, Euler density and Weyl tensor squared, we pursue the possibility that it is given by Ricci scalar and Hirzebruch-Pontryagin density. It has a deep connection with scale but non-conformal field theories and their holographic dual. I would like to urge you to judge whether such holographic theories are consistent or pathological.

The photo-production of J/ψ near threshold is a promising process to access the contribution from the gluon condensate to the proton mass. We study this process in a holographic model and compare our result with the latest experimental data from the GlueX collaboration.

The evaporation of four-dimensional spherically symmetric black holes is presented in the framework of quantum field theory in curved spacetimes and semiclassical gravity. It is discussed how the evaporation process can be sourced by the presence of the trace anomaly of a massless, conformally coupled scalar field outside the apparent horizon of the black hole.

The trace anomaly of conformal matter implies the existence of massless scalar poles in physical amplitudes involving the stress-energy tensor. These poles may be described by a local effective action with massless scalar fields, which couple to classical sources, contribute to gravitational scattering processes, and can have long range gravitational effects at macroscopic scales. In an effective field theory approach, the effective action of the anomaly is an infrared relevant term that should be added to the Einstein-Hilbert action of classical General Relativity to take account of macroscopic quantum effects. The additional scalar degrees of freedom contained in this effective action may be understood as responsible for both the Casimir effect in flat spacetime and large quantum backreaction effects at the horizon scale of cosmological spacetimes. These effects of the trace anomaly imply that the cosmological vacuum energy is dynamical, and its value depends on macroscopic boundary conditions at the cosmological horizon scale, rather than sensitivity to the extreme ultraviolet Planck scale.

We revisit the asymptotically Anti de Sitter spacetimes in three dimensions. Using the conformal-completion technique, we formulate the boundary conditions in a covariant fashion and construct the global charges associated with the asymptotic symmetries. The charges so constructed are conserved for the asymptotic Killing vectors fields but are not conserved for the asymptotic conformal Killing vector fields. The quantity integrated to obtain the global charge is interpreted as the Brown-York boundary stress-energy tensor and it is found not to be traceless. The trace is interpreted as the Trace Anomaly and it turns out to be the same as the Brown-Henneaux central charge.