29 citations · 33 across the 3 of their papers we have counts for
7 papers
Simplified diagrammatic expansion for effective operator
Chang-Kui Duan, Yungui Gong, Hui-Ning Dong +1
For a quantum many-body problem, effective Hamiltonians that give exact eigenvalues in reduced model space usually have different expressions, diagrams and evaluation rules from ef…
Conservation of connectivity of model-space effective interactions under a class of similarity transformation
Chang-Kui Duan, Yungui Gong, Hui-Ning Dong +1
Effective interaction operators usually act on a restricted model space and give the same energies (for Hamiltonian) and matrix elements (for transition operators etc.) as those of…
Constraints on alternative models to dark energy
Yungui Gong, Chang-Kui Duan
The recent observations of type Ia supernovae strongly support that the universe is accelerating now and decelerated in the recent past. This may be the evidence of the breakdown o…
Brane Universe and Standard Cosmology
Yungui Gong
Brane cosmology takes the unconventional form . To recover the standard cosmology, we have to assume that the matter density is much less than the brane tension. We s…
Equivalent frames in Brans-Dicke theory
Yungui Gong
We discuss the physical equivalence between the Einstein and Jordan frames in Brans-Dicke theory. The inequivalence of conformal transformed theories is clarified with the help of…
Ramond-Ramond Field Transformation
Yungui Gong
We find that the mixture of Ramond-Ramond fields and Neveu-Schwarz two form are transformed as Majorana spinors under the T-duality group . The Ramond-Ramond field transfor…