论文标题
$λ$ -BMS $ _4 $充电代数
The $Λ$-BMS$_4$ Charge Algebra
论文作者
论文摘要
在本地（a）ds $ _4 $ spaceTimes毫无疑问的情况下，无物质的表面电荷代数（a）ds $ _4 $ spaceTimes无需假设任何边界条件。与Weyl recrecalings相关的表面电荷正在消失，而边界差异电荷代数则在没有中央延伸的情况下非平整表示。 $λ$ -BMS $ _4 $充电代数是在指定边界叶面和边界度量之后获得的。固定极限的存在需要从边界叶约和度量定义的动作和符号结构中添加角项。然后，固定限制重现了BMS $ _4 $电荷代数的超级翻译和超级洛伦兹的转换，该转换作用于渐近本地平坦的空间。 BMS $ _4 $的表面费用代表BMS $ _4 $代数，而在标准Dirac支架下的Null Infinity的Corners corners not Contral Extension表示，这意味着BMS $ _4 $ FLUX代数承认没有非平底的中央扩展。
The surface charge algebra of generic asymptotically locally (A)dS$_4$ spacetimes without matter is derived without assuming any boundary conditions. Surface charges associated with Weyl rescalings are vanishing while the boundary diffeomorphism charge algebra is non-trivially represented without central extension. The $Λ$-BMS$_4$ charge algebra is obtained after specifying a boundary foliation and a boundary measure. The existence of the flat limit requires the addition of corner terms in the action and symplectic structure that are defined from the boundary foliation and measure. The flat limit then reproduces the BMS$_4$ charge algebra of supertranslations and super-Lorentz transformations acting on asymptotically locally flat spacetimes. The BMS$_4$ surface charges represent the BMS$_4$ algebra without central extension at the corners of null infinity under the standard Dirac bracket, which implies that the BMS$_4$ flux algebra admits no non-trivial central extension.
