Category: Theoretical physics
Modular symmetry shapes quintessence and de Sitter vacua
What the study found Modular symmetry in heterotic orbifolds was found to shape a scalar potential with a rich vacuum structure. The authors report anti-de Sitter minima, unstable de Sitter saddle points, and large regions in moduli space supporting multifield hilltop quintessence. Why the authors say this matters The authors conclude that modular symmetry can…
Interacting dark energy and dark matter models fit current data
What the study found The study found that two versions of a cosmological model with interacting dark energy and dark matter can fit current observations well. The models use a Gauss–Bonnet-coupled scalar field as dark energy and a fermionic dark matter field, with either an exponential or a power-law scalar potential. Why the authors say…
Adjoint QCD2 can exhibit supersymmetry at specific fermion masses
What the study found The study finds that a 1+1-dimensional SU(N) gauge theory with an adjoint Majorana fermion, called adjoint QCD2, exhibits supersymmetry when the fermion mass is set to a specific value. It also identifies related models in which a supersymmetric massive sector coexists with a non-supersymmetric conformal field theory (CFT, a theory describing…
Massive Type IIA solutions model monodromy defects in 5d and 6d theories
What the study found The study proposes massive Type IIA supergravity solutions as duals of co-dimension 2 monodromy defects in 6d (1,0) conformal field theories and in the 5d Sp(N) fixed point theory. It also reports evidence that, for 3d defects, the defect entanglement entropy can be written as a linear combination of the defect…
Kerr-de Sitter black holes show stronger repetitive energy return
What the study found The study found that, compared with a Kerr black hole, a Kerr-de Sitter black hole can produce higher energy return on investment (EROI) and higher single-extraction energy capability in the repetitive Penrose process. The results also depend on the cosmological parameter and the decay radius. Why the authors say this matters…
Heterotic supergravity deformations are constructed with vector methods
What the study found The authors constructed bi- and uni-vector deformations of 10d heterotic supergravity solutions. They also generalized the "open/closed" map for this setting and examined examples of the resulting deformed solutions, especially for the F1 string solution. Why the authors say this matters The abstract does not state a broader significance or application…
Weak gravity bound extended to AdS settings
What the study found The authors extend a recent proposal for the Weak Gravity Conjecture (WGC) in anti-de Sitter (AdS) space to more general effective field theories. They report that, when moduli are present, the relevant condition is that a particle produced by Schwinger effect during an extremal black hole decay is repelled close to…
Localized BFSS phases are linked to instability and phase transitions
What the study found The study finds that the recently discovered localized and non-uniform phases of BFSS matrix quantum mechanics can be derived from first principles. It also finds that the uniform BFSS phase corresponds to a black string in a pp-wave background, which is unstable to a Gregory-Laflamme instability. Why the authors say this…
Wavefunction collapse is proposed as a source of time and emergent gravity modes
What the study found The paper develops a proposed theory in which wavefunction collapse in general relativity gives rise to time. In this framework, quantum states that violate the momentum and Hamiltonian constraints represent instances of time, and stochastic fluctuations of the lapse and shift drive evolution toward a diffeomorphism-invariant state. Why the authors say…
Starobinsky model remains viable in parts of parameter space
What the study found The authors report that, despite recent data placing pressure on the pure Starobinsky inflation model, there is still a significant region of parameter space where the model remains highly consistent with the latest observations. They also say that adding a cubic $R^3$ term can shift the model's predictions toward better agreement…