scholarly journals Trace Anomaly and Nonlocal Effective Action for 2-D Conformally Invariant Scalar Interacting with Dilaton

1997 ◽  
Vol 12 (28) ◽  
pp. 2083-2087 ◽  
Author(s):  
Shin'ichi Nojiri ◽  
Sergei D. Odintsov

Using the results of the calculation of the one-loop effective action (E. Elizalde et al., Phys. Rev.D49, 2852 (1994)), we find the trace anomaly for most general conformally invariant 2-D dilaton coupled scalar–dilaton system (the contribution of dilaton itself is included). The nonlocal effective action induced by conformal anomaly for such system is found. That opens new possibilities in generalizing of CGHS-like model for the study of back-reaction of matter to 2-D black holes.

1999 ◽  
Vol 14 (08) ◽  
pp. 1293-1304 ◽  
Author(s):  
SHIN'ICHI NOJIRI ◽  
SERGEI D. ODINTSOV

We study the one-loop effective action for N 4D conformally invariant scalars on the spherically symmetric background. The main part of the effective action is given by integration of the 4D conformal anomaly. This effective action (in large N approximation and partial curvature expansion) is applied to investigate the quantum evolution of Schwarzschild–de Sitter (SdS) black holes of maximal mass. We find that the effect (recently discovered by Bousso and Hawking for N minimal scalars and another approximate effective action) of antievaporation of nearly maximal SdS (Nariai) black holes also occurs in the model under consideration. Careful treatment of quantum corrections and perturbations modes of Nariai black holes is given, being quite complicated. It is shown that exists also perturbation where the black hole radius shrinks, i.e. the black hole evaporates. We point out that our result holds for a wide class of models, including conformal scalars, spinors and vectors. Hence, antievaporation of SdS black holes is a rather general effect which should be taken into account in quantum gravity considerations.


Universe ◽  
2018 ◽  
Vol 4 (11) ◽  
pp. 125 ◽  
Author(s):  
Lesław Rachwał

Conformal symmetry always played an important role in field theory (both quantum and classical) and in gravity. We present construction of quantum conformal gravity and discuss its features regarding scattering amplitudes and quantum effective action. First, the long and complicated story of UV-divergences is recalled. With the development of UV-finite higher derivative (or non-local) gravitational theory, all problems with infinities and spacetime singularities might be completely solved. Moreover, the non-local quantum conformal theory reveals itself to be ghost-free, so the unitarity of the theory should be safe. After the construction of UV-finite theory, we focused on making it manifestly conformally invariant using the dilaton trick. We also argue that in this class of theories conformal anomaly can be taken to vanish by fine-tuning the couplings. As applications of this theory, the constraints of the conformal symmetry on the form of the effective action and on the scattering amplitudes are shown. We also remark about the preservation of the unitarity bound for scattering. Finally, the old model of conformal supergravity by Fradkin and Tseytlin is briefly presented.


2001 ◽  
Vol 16 (06) ◽  
pp. 1015-1108 ◽  
Author(s):  
SHIN'ICHI NOJIRI ◽  
SERGEI D. ODINTSOV

We review (mainly) quantum effects in the theories where the gravity sector is described by metric and dilaton. The one-loop effective action for dilatonic gravity in two and four dimensions is evaluated. Renormalization group equations are constructed. The conformal anomaly and induced effective action for 2d and 4d dilaton coupled theories are found. It is applied to the study of quantum aspects of black hole thermodynamics, like calculation of Hawking radiation and quantum corrections to black hole parameters and investigation of quantum instability for such objects with multiple horizons. The use of the above effective action in the construction of nonsingular cosmological models in Einstein or Brans–Dicke (super)gravity and investigation of induced wormholes in supersymmetric Yang–Mills theory are given.5d dilatonic gravity (bosonic sector of compactified IIB supergravity) is discussed in connection with bulk/boundary (or AdS/CFT) correspondence. Running gauge coupling and quark–antiquark potential for boundary gauge theory at zero or nonzero temperature are calculated from d=5 dilatonic anti-de Sitter-like background solution which represents anti-de Sitter black hole for periodic time.


1997 ◽  
Vol 12 (13) ◽  
pp. 925-935 ◽  
Author(s):  
Shin'ichi Nojiri ◽  
Sergei D. Odintsov

We study the effective action in 2-D dilaton-Maxwell quantum gravity. Working with the one-loop renormalizable subset of such theories, we construct the improved effective Lagrangian which contains curvature under logarithm. This effective Lagrangian leads to new classical dilatonic gravity inspired by quantum effects. The static black holes (BH) solutions which may play the role of a remnant after the Hawking radiation for such theory are carefully investigated. The effective Lagrangian for Gross–Neveu-dilaton gravity is also constructed (in 1/N expansion).


2005 ◽  
Vol 20 (05) ◽  
pp. 1027-1064 ◽  
Author(s):  
GEORGE TSOUPROS

The trace anomaly for a conformally invariant scalar field theory on a curved manifold of positive constant curvature with boundary is considered. In the context of a perturbative evaluation of the theory's effective action explicit calculations are given for those contributions to the conformal anomaly which emerge as a result of free scalar propagation as well as from scalar self-interactions up to second order in the scalar self-coupling. The renormalization-group behavior of the theory is, subsequently, exploited in order to advance the evaluation of the conformal anomaly to third order in the scalar self-coupling. As a direct consequence the effective action is evaluated to the same order. In effect, complete contributions to the theory's conformal anomaly and effective action are evaluated up to fourth-loop order.


2017 ◽  
Vol 32 (35) ◽  
pp. 1750204 ◽  
Author(s):  
Gao-Ming Deng ◽  
Yong-Chang Huang

The phase transition and critical behaviors of charged AdS black holes in [Formula: see text] gravity with a conformally invariant Maxwell (CIM) source and constant curvature are further investigated. As a highlight, this research is carried out by employing new state parameters [Formula: see text] and contributes to deeper understanding of the thermodynamics and phase structure of black holes. Our analyses manifest that the charged [Formula: see text]-CIM AdS black hole undergoes a first-order small–large black hole phase transition, and the critical behaviors qualitatively behave like a Van der Waals liquid–vapor system. However, differing from the case in Einstein’s gravity, phase structures of the black holes in [Formula: see text] theory exhibit an interesting dependence on gravity modification parameters. Moreover, we adopt the thermodynamic geometry to probe the black hole microscopic properties. The results show that, on the one hand, both the Ruppeiner curvature and heat capacity diverge exactly at the critical point, on the other hand, the [Formula: see text]-CIM AdS black hole possesses the property as ideal Fermi gases. Of special interest, we discover a microscopic similarity between the black holes and a Van der Waals liquid–vapor system.


1995 ◽  
Vol 439 (3) ◽  
pp. 561-582 ◽  
Author(s):  
A.O. Barvinsky ◽  
Yu.V. Gusev ◽  
G.A. Vilkovisky ◽  
V.V. Zhytnikov

2017 ◽  
Vol 26 (1) ◽  
Author(s):  
ChengZhou Liu ◽  
HaiWen Liu

AbstractSpectroscopy for a modified Schwarzschild black hole in noncommutative spacetimes is investigated. By utilizing an action invariance of black holes, the equally spaced entropy spectrum characteristic of Bekenstein’s original derivation is recovered. The derived spectrum is independent of the noncommutative parameter θ, and holds for all the existed noncommutative black holes independent of mass. On the other hand, the obtained area spectrum is not always equidistant due to the noncommutativity effects of the modified spacetimes. For large black holes, the equally spaced area spectrum spectrum can be obtained at the leading order in θ. But, for small black holes, the derived area spectrum is not equidistant, and it depends the noncommutative parameter. In addition, the one loop back reaction effect on the spectroscopy of the noncommutative Schwarzschild black hole is discussed. In this calculation, due to the back reaction effect, the equidistant area spectrum can not be obtained for all the noncommutative black holes with both large and small mass. Conversely, the back reaction effect has no influence on the entropy spectrum. The obtained entropy spectrum is equidistant and consistent with the original Bekenstein’s spectrum for all the existed noncommutative Schwarzschild black holes.


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