Physics Letters B 737 (2014) 272–276
Contents lists available at ScienceDirect
Physics Letters B
www.elsevier.com/locate/physletb
Generalized dilatation operator method for non-relativistic holography
Wissam Chemissany
a
, Ioannis Papadimitriou
b,∗
a
Department of Physics and SITP, Stanford University, Stanford, CA 94305, USA
b
Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, Madrid 28049, Spain
a r t i c l e i n f o a b s t r a c t
Article history:
Received
16 August 2014
Accepted
25 August 2014
Available
online 28 August 2014
Editor:
M. Cveti
ˇ
c
We present a general algorithm for constructing the holographic dictionary for Lifshitz and hyperscaling
violating Lifshitz backgrounds for any value of the dynamical exponent z and any value of the
hyperscaling violation parameter θ compatible with the null energy condition. The objective of the
algorithm is the construction of the general asymptotic solution of the radial Hamilton–Jacobi equation
subject to the desired boundary conditions, from which the full dictionary can be subsequently derived.
Contrary to the relativistic case, we find that a fully covariant construction of the asymptotic solution
for running non-relativistic theories necessitates an expansion in the eigenfunctions of two commuting
operators instead of one. This provides a covariant but non-relativistic grading of the expansion, according
to the number of time derivatives.
© 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/3.0/). Funded by SCOAP
3
.
1. Introduction
In recent years, great effort has been devoted to the use of
holographic models in order to gain a deeper understanding of
the strong coupling physics in condensed matter systems. The
gauge/gravity duality has proven an instrumental tool in study-
ing
the strongly coupled dynamics near quantum critical points
exhibiting Lifshitz [1,2] or Schrödinger [3,4] symmetry. More re-
cently,
gravity duals to non-relativistic systems that transform non-
trivially
under scale transformations have been put forward [5–8].
The geometries dual to such hyperscaling violating Lifshitz (hvLf)
quantum systems are of the form
ds
2
d
+2
=
du
2
−u
−2(z−1)
dt
2
+d
x
2
−2
u
2(d−θ)/d
, (1)
where d is the spatial dimension, z and θ are respectively the Lif-
shitz
and hyperscaling violation exponents, and is the Lifshitz
radius. This metric transforms non-trivially under scale transfor-
mations
as
x →λ
x, t →λ
z
t, u → λu, ds
2
d
+2
→λ
2θ
d
ds
2
d
+2
. (2)
By computing the energy of supergravity fluctuations around the
background (1) one can unambiguously determine the location of
*
Corresponding author.
E-mail
addresses: wissam@stanford.edu (W. Chemissany),
ioannis.papadimitriou@csic.es (I. Papadimitriou).
the ultraviolet (UV) of the dual quantum field theory, correspond-
ing
to the conformal boundary of the geometry (1), to be at u →0,
independently of the value of the exponents z and θ [7,9]. The only
restriction we shall impose on the exponents z and θ is the null
energy condition, which leads to seven distinct cases for the val-
ues
of z and θ [10]. However, the only two solutions that allow for
z < 1require θ>d + z, in which case the on-shell action is UV fi-
nite
and as a result there are no well defined Fefferman–Graham
asymptotic expansions [10]. The marginal case θ = d + z requires
separate analysis. Our discussion here and in [10] therefore focuses
on the case z > 1.
For
earlier work on asymptotically Lifshitz backgrounds, their
hyperscaling violating versions and various string theory embed-
dings
we refer the reader to the following recent papers and refer-
ences
therein [11–15]. The literature primarily relevant to us here
though concerns earlier work on holographic renormalization and
the holographic dictionary for asymptotically Lifshitz backgrounds.
In particular, holography for the Einstein–Proca theory with Lif-
shitz
boundary conditions has been discussed from a bottom up
perspective in [16–23], while in [24–30] AdS embeddings (or lim-
its)
of Lifshitz backgrounds were utilized in order to deduce the
non-relativistic dictionary from the relativistic one in special cases.
Our
aim in this Letter and the accompanying main paper [10]
is
to present a general algorithm for the construction of the holo-
graphic
dictionary of non-relativistic theories, that can be applied
to theories with or without a UV fixed point and for any value
of the dynamical exponents that is consistent with the null en-
ergy
condition. The main tool for deriving the holographic dic-
tionary,
which includes the Fefferman–Graham expansions, the
http://dx.doi.org/10.1016/j.physletb.2014.08.057
0370-2693/
© 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/). Funded by
SCOAP
3
.