31 citations · 255 across the 24 of their papers we have counts for
24 papers
Note on tree NLSM amplitudes and soft theorems
Kang Zhou, Fang-Stars Wei
We use the universality of single soft behavior, together with the double copy structure, to completely determine the tree amplitudes of non-linear sigma model (NLSM). We first fig…
Expanding single trace YMS amplitudes with gauge invariant coefficients
Fang-Stars Wei, Kang Zhou
In this note, we use the new bottom up method based on soft theorems to construct the expansion of single-trace Yang-Mills-scalar amplitudes recursively. The resulted expansion man…
Tree and -loop fundamental BCJ relations from soft theorems
Fang-Stars Wei, Kang Zhou
We provide a new derivation of the fundamental BCJ relation among double color ordered tree amplitudes of bi-adjoint scalar theory, based on the leading soft theorem for external s…
Tree level amplitudes from soft theorems
Kang Zhou
We demonstrate that the tree level amplitudes and the explicit formulas of soft factors can be uniquely determined by soft theorems and the universality of soft factors. By imposin…
Transmutation operators and expansions for -loop Feynman integrands
Kang Zhou
In this paper, the connections among -loop Feynman integrands of a large variety of theories with massless external states are further investigated. The work includes two parts.…
On differential operators and unifying relations for -loop Feynman integrands
Kang Zhou
We generalize the unifying relations for tree amplitudes to the -loop Feynman integrands. By employing the -loop CHY formula, we construct differential operators which transm…
Note on scalar-graviton and scalar-photon-graviton amplitudes
Kang Zhou, Guo-Jun Zhou
In this short note, we propose an algorithm based on the expansions of amplitudes, the dimensional reduction technic and the differential operators, to calculate the tree level sca…
Transmuting off-shell CHY integrals in the double-cover framework
Kang Zhou, Guo-Jun Zhou
In this paper, by defining off-shell amplitudes as off-shell CHY integrals, and redefining the longitudinal operator, we demonstrate that the differential operators which link on-s…
Factorizations for tree amplitudes in the double-cover framework: from gravity to other theories
Kang Zhou
In this paper, we demonstrate that the factorizations for tree amplitudes in the double-cover framework, for various theories, can be generated from the gravity amplitude in the do…
Unified web for expansions of amplitudes
Kang Zhou
In this paper, we demonstrate that using differential operators one can construct the complete unified web for expansions of amplitudes for a wide range of theories. We first re-de…
Expansion of tree amplitudes for EM and other theories
Shi-Qian Hu, Kang Zhou
The expansions of tree-level amplitudes for one theory into amplitudes for another theory, which have been studied in various recent literatures, exhibit hidden connections between…
Expansion of Einstein-Yang-Mills theory by Differential Operators
Bo Feng, Xiaodi Li, Kang Zhou
The factorization form of the integrands in the Cachazo-He-Yuan (CHY) formalism makes the generalized Kawai-Lewellen-Tye (KLT) relations manifest, thus amplitudes of one theory can…
Note on differential operators, CHY integrands, and unifying relations for amplitudes
Kang Zhou, Bo Feng
An elegant unified web for amplitudes of various theories was given by Cachazo, He and Yuan in the CHY framework a few years ago. Recently, similar web has also been constructed by…
Derivation of Feynman Rules for Higher Order Poles Using Cross-ratio Identities in CHY Construction
Kang Zhou, Junjie Rao, Bo Feng
In order to generalize the integration rules to general CHY integrands which include higher order poles, algorithms are proposed in two directions. One is to conjecture new rules,…
Analytic expressions of amplitudes by the cross-ratio identity method
Kang Zhou
In order to obtain the analytic expression of an amplitude from a generic CHY-integrand, a new algorithm based on the so-called cross-ratio identities has been proposed recently. I…
The Q-cut Representation of One-loop Integrands and Unitarity Cut Method
Rijun Huang, Qingjun Jin, Junjie Rao +2
Recently, a new construction for complete loop integrands of massless field theories has been proposed, with on-shell tree-level amplitudes delicately incorporated into its algorit…
On Multi-step BCFW Recursion Relations
Bo Feng, Junjie Rao, Kang Zhou
In this paper, we extensively investigate the new algorithm known as the multi-step BCFW recursion relations. Many interesting mathematical properties are found and understanding t…
Determination of Boundary Contributions in Recursion Relation
Bo Feng, Kang Zhou, Chenkai Qiao +1
In this paper, we propose a new algorithm to systematically determine the missing boundary contributions, when one uses the BCFW on-shell recursion relation to calculate tree ampli…
General tree-level amplitudes by factorization limits
Kang Zhou, Chenkai Qiao
To find boundary contributions is a rather difficult problem when applying the BCFW recursion relation. In this paper, we propose an approach to bypass this problem by calculating…
Integral Reduction by Unitarity Method for Two-loop Amplitudes: A Case Study
Bo Feng, Jun Zhen, Rijun Huang +1
In this paper, we generalize the unitarity method to two-loop diagrams and use it to discuss the integral bases of reduction. To test out method, we focus on the four-point double-…
Spontaneous Symmetry Breaking Vacuum Energy in Cosmology
Kang Zhou, Rui-Hong Yue, Zhan-Ying Yang +1
In present paper the gravitational effect of spontaneous symmetry breaking vacuum energy density is investigated by subtracting the flat space-time contribution from the energy in…
Spherically symmetric gravitational collapse of a dust cloud in third order Lovelock Gravity
Kang Zhou, Zhan-Ying Yang, De-Cheng Zou +1
We investigate the spherically symmetric gravitational collapse of an incoherent dust cloud by considering a LTB type space-time in third order Lovelock Gravity without cosmologica…
Spherically symmetric gravitational collapse of a dust cloud in Einstein-Gauss-Bonnet Gravity
Kang Zhou, Zhan-Ying Yang, De-Cheng Zou +1
We explore the gravitational collapse of a spherically symmetric dust cloud in the Einstein-Gauss-Bonnet gravity without a cosmological constant, and obtain three families of LTB-l…
Static spherically symmetric star in Gauss-Bonnet gravity
Kang Zhou, Zhan-Ying Yang, De-Cheng Zou +1
We explore static spherically symmetric stars in the Gauss-Bonnet gravity without cosmological constant, and present an exact internal solution which attaches to the exterior vacuu…