23 research outputs found
T-dual RR couplings on D-branes from S-matrix elements
Using the linear T-dual ward identity associated with the NSNS gauge
transformations, some RR couplings on D-branes have been found at order
. We examine the couplings with the S-matrix elements
of one RR, one graviton and one antisymmetric B-field vertex operators. We find
the consistency of T-dual S-matrix elements and explicit results of scattering
string amplitude and show that the string amplitude reproduces these couplings
as well as some other couplings. This illustration is found for
couplings in the literature which is extended to the couplings in
this paper.Comment: 23 pages. V2: it appears in PR
S-dual Amplitude and D3-Brane Couplings
Recently, it has been observed that the IIB scattering amplitudes are
compatible with the standard rules of S-duality. Inspired by this observation,
we will find the tree-level S-matrix elements of one Ramond-Ramond and three
open strings by imposing this symmetry on the tree-level S-matrix elements of
one Kalb-Ramond and three open strings. We also find a SL(2, R) invariant form
of the D3-brane effective action containing four gauge fields with derivative
corrections that was derived from one-loop level four-point amplitude. Using
the expansion of the nonlinear SL(2, R) invariant structures, we find the
action with derivative corrections at the level of more gauge fieldsComment: 18 page
Ramond-Ramond S-matrix elements from T-dual Ward identity
Recently it has been speculated that the Ward identities associated with the
string dualities and the gauge symmetries can be used as guiding principles to
find all components of the scattering amplitude of supergravitons from a
given component of the S-matrix. In this paper, we apply the Ward identities
associated with the T-duality and the gauge symmetries on the disk-level
S-matrix element of one RR -form, one NSNS and one NS states, to find
the corresponding S-matrix elements of the RR -form, -form or the
RR-form on the world volume of a D-brane. Moreover, we apply these
Ward identities on the S-matrix element of one RR -form and two NSNS
states to find the corresponding S-matrix elements of the RR -form,
-form, -form or the RR -form.Comment: 40 pages, Latex file, no figur
Dilaton Black Hole Entropy from Entropy Function Formalism
It has been shown that the entropy function formalism is an efficient way to
calculate the entropy of black holes in string theory. We check this formalism
for the extremal charged dilaton black hole. We find the general
four-derivative correction on the black hole entropy from the value of the
entropy function at its extremum point.Comment: 11 page
Complexity and Near Extremal Charged Black Branes
We compute holographic complexity of charged black brane solutions in
arbitrary dimensions for the near horizon limit of near extremal case using two
different methods. The corresponding complexity may be obtained either by
taking the limit from the complexity of the charged black brane, or by
computing the complexity for near horizon limit of near extremal solution. One
observes that these results coincide if one assumes to have a cutoff behind
horizon whose value is fixed by UV cutoff and also taking into account a proper
counterterm evaluated on this cutoff. We also consider the situation for Vaidya
charged black branes too.Comment: 20 pages, 3 figs, Ref.s adde
S-matrix elements from T-duality
Recently it has been speculated that the S-matrix elements satisfy the Ward
identity associated with the T-duality. This indicates that a group of S-matrix
elements is invariant under the linear T-duality transformations on the
external states. If one evaluates one component of such T-dual multiplet, then
all other components may be found by the simple use of the linear T-duality.
The assumption that fields must be independent of the Killing coordinate,
however, may cause, in some cases, the T-dual multiplet not to be gauge
invariant. In those cases, the S-matrix elements contain more than one T-dual
multiplet which are intertwined by the gauge symmetry.
In this paper, we apply the T-dual Ward identity on the S-matrix element of
one RR -form and two NSNS states on the world volume of a D-brane to
find its corresponding T-dual multiplet. In the case that the RR potential has
two transverse indices, the T-dual multiplet is gauge invariant, however, in
the case that it has one transverse index the multiplet is not gauge invariant.
We find a new T-dual multiplet in this case by imposing the gauge symmetry.
We show that the multiplets are reproduced by explicit calculation, and their
low energy contact terms at order are consistent with the existing
couplings in the literature.Comment: 33 pages, Latex file, the version appears in NP
Subregion Action and Complexity
We evaluate finite part of the on-shell action for black brane solutions of
Einstein gravity on different subregions of spacetime enclosed by null
boundaries. These subregions include the intersection of WDW patch with
past/future interior and left/right exterior for a two sided black brane.
Identifying the on-shell action on the exterior regions with subregion
complexity one finds that it obeys subadditivity condition. This gives an
insight to define a new quantity named mutual complexity. We will also consider
certain subregion that is a part of spacetime which could be causally connected
to an operator localized behind/outside the horizon. Taking into account all
terms needed to have a diffeomorphism invariant action with a well-defined
variational principle, one observes that the main contribution that results to
a nontrivial behavior of the on-shell action comes from joint points where two
lightlike boundaries (including horizon) intersect. A spacelike boundary gives
rise to a linear time growth, while we have a classical contribution due to a
timelike boundary that is given by the free energy.Comment: 26 pages, 5 figures, v2: typos corrected, references added, v3:
matches published versio
Evolution of Entanglement Wedge Cross Section Following a Global Quench
We study the evolution of entanglement wedge cross section (EWCS) in the
Vaidya geometry describing a thin shell of null matter collapsing into the AdS
vacuum to form a black brane. In the holographic context, it is proposed that
this quantity is dual to different information measures including entanglement
of purification, reflected entropy, odd entropy and logarithmic negativity. In
2+1 dimensions, we present a combination of numerical and analytic results on
the evolution and scaling of EWCS for strip shaped boundary subregions after a
thermal quench. In the limit of large subregions, we find that the time
evolution of EWCS is characterized by three different scaling regimes: an early
time quadratic growth, an intermediate linear growth and a late time
saturation. Further, in 3+1 dimensions, we examine the scaling behavior by
considering thermal and electromagnetic quenches. In the case of a thermal
quench, our numerical analysis supply results similar to observations made for
the lower dimension. On the other hand, for electromagnetic quenches at zero
temperature, an interesting feature is a departure from the linear behavior of
the evolution to logarithmic growth.Comment: 38 pages, 18 figures, v2: matches JHEP versio
Some Aspects of Entanglement Wedge Cross-Section
We consider the minimal area of the entanglement wedge cross section (EWCS)
in Einstein gravity. In the context of holography, it is proposed that this
quantity is dual to different information measures, e.g., entanglement of
purification, logarithmic negativity and reflected entropy. Motivated by these
proposals, we examine in detail the low and high temperature corrections to
this quantity and show that it obeys the area law even in the finite
temperature. We also study EWCS in nonrelativistic field theories with
nontrivial Lifshitz and hyperscaling violating exponents. The resultant EWCS is
an increasing function of the dynamical exponent due to the enhancement of
spatial correlations between subregions for larger values of . We find that
EWCS is monotonically decreasing as the hyperscaling violating exponent
increases. We also obtain this quantity for an entangling region with singular
boundary in a three dimensional field theory and find a universal contribution
where the coefficient depends on the central charge. Finally, we verify that
for higher dimensional singular regions the corresponding EWCS obeys the area
law.Comment: 31 pages, 10 figures, title changed, updated to match the published
versio
Emergence of non-linear electrodynamic theories from -like deformations
In this letter, we investigate the deformation of the ModMax theory, as a
unique Lagrangian of non-linear electrodynamics preserving both conformal and
electromagnetic-duality invariance, under -like flows. We will show
that the deformed theory is the generalized non-linear Born-Infeld
electrodynamics. Being inspired by the invariance under the flow equation for
Born-Infeld theories, we propose another -like operator generating
the ModMax and generalized Born-Infeld non-linear electrodynamic theories from
the usual Maxwell and Born-Infeld theories, respectively.Comment: 12 pages, 1 figure, Accepted for publication in PL