scholarly journals Quantum Fluctuations and the Unruh effect in strongly-coupled conformal field theories

2010 ◽  
Vol 2010 (6) ◽  
Author(s):  
Elena Cáceres ◽  
Mariano Chernicoff ◽  
Alberto Güijosa ◽  
Juan F. Pedraza
2011 ◽  
Vol 84 (6) ◽  
Author(s):  
Christiana Athanasiou ◽  
Paul M. Chesler ◽  
Hong Liu ◽  
Dominik Nickel ◽  
Krishna Rajagopal

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
G. Cuomo ◽  
A. Esposito ◽  
E. Gendy ◽  
A. Khmelnitsky ◽  
A. Monin ◽  
...  

Abstract At finite density, the spontaneous breakdown of an internal non-Abelian symmetry dictates, along with gapless modes, modes whose gap is fixed by the algebra and proportional to the chemical potential: the gapped Goldstones. Generically the gap of these states is comparable to that of other non-universal excitations or to the energy scale where the dynamics is strongly coupled. This makes it non-straightforward to derive a universal effective field theory (EFT) description realizing all the symmetries. Focusing on the illustrative example of a fully broken SU(2) group, we demonstrate that such an EFT can be constructed by carving out around the Goldstones, gapless and gapped, at small 3-momentum. The rules governing the EFT, where the gapless Goldstones are soft while the gapped ones are slow, are those of standard nonrelativistic EFTs, like for instance nonrelativistic QED. In particular, the EFT Lagrangian formally preserves gapped Goldstone number, and processes where such number is not conserved are described inclusively by allowing for imaginary parts in the Wilson coefficients. Thus, while the symmetry is manifestly realized in the EFT, unitarity is not. We comment on the application of our construction to the study of the large charge sector of conformal field theories with non-Abelian symmetries.


2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Yifan Wang

Abstract Quantum field theories (QFT) in the presence of defects exhibit new types of anomalies which play an important role in constraining the defect dynamics and defect renormalization group (RG) flows. Here we study surface defects and their anomalies in conformal field theories (CFT) of general spacetime dimensions. When the defect is conformal, it is characterized by a conformal b-anomaly analogous to the c-anomaly of 2d CFTs. The b-theorem states that b must monotonically decrease under defect RG flows and was proven by coupling to a spurious defect dilaton. We revisit the proof by deriving explicitly the dilaton effective action for defect RG flow in the free scalar theory. For conformal surface defects preserving $$ \mathcal{N} $$ N = (0, 2) supersymmetry, we prove a universal relation between the b-anomaly and the ’t Hooft anomaly for the U(1)r symmetry. We also establish the b-extremization principle that identifies the superconformal U(1)r symmetry from $$ \mathcal{N} $$ N = (0, 2) preserving RG flows. Together they provide a powerful tool to extract the b-anomaly of strongly coupled surface defects. To illustrate our method, we determine the b-anomalies for a number of surface defects in 3d, 4d and 6d SCFTs. We also comment on manifestations of these defect conformal and ’t Hooft anomalies in defect correlation functions.


2010 ◽  
Vol 81 (12) ◽  
Author(s):  
Christiana Athanasiou ◽  
Paul M. Chesler ◽  
Hong Liu ◽  
Dominik Nickel ◽  
Krishna Rajagopal

2011 ◽  
Vol 84 (10) ◽  
Author(s):  
V. Balasubramanian ◽  
A. Bernamonti ◽  
N. Copland ◽  
B. Craps ◽  
F. Galli

2013 ◽  
Vol 2013 (4) ◽  
Author(s):  
V. Balasubramanian ◽  
A. Bernamonti ◽  
B. Craps ◽  
V. Keränen ◽  
E. Keski-Vakkuri ◽  
...  

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Michele Redi ◽  
Andrea Tesi

Abstract We use the framework of relativistic and non-relativistic conformal field theories (CFT) to derive general results relevant for the production of weakly coupled and strongly coupled dark sectors through thermal interactions. Our result reproduce trivially known formulas for 2 → n processes and extend to general m → n processes as well as interacting dark sectors. As concrete examples we consider freeze-in of a relativistic CFT coupled to the SM with contact interactions and derive Sommerfeld enhancement of non-relativistic cross-sections from the theory of fermions at unitarity.


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Enrico M. Brehm

Abstract We investigate perturbatively tractable deformations of topological defects in two-dimensional conformal field theories. We perturbatively compute the change in the g-factor, the reflectivity, and the entanglement entropy of the conformal defect at the end of these short RG flows. We also give instances of such flows in the diagonal Virasoro and Super-Virasoro Minimal Models.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Hugo A. Camargo ◽  
Lucas Hackl ◽  
Michal P. Heller ◽  
Alexander Jahn ◽  
Tadashi Takayanagi ◽  
...  

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