arXiv subjects

Aalok Misra

Publications and source records attributed to Aalok Misra.

At least 19 recordsLinked to original sources

arXiv2026

Contact Structure-induced Symplectic Nearly Half-Flat $SU(3)$ Structure in Finite-$N$ Thermal ${\cal M}$-Theory

The ${\cal M}$-theory dual of thermal QCD-like theories constructed in arXiv:1306.4339, 2004.07259 involves, as shown in arXiv:2211.13186, a closed $G_2$-structure seven-fold $\mathcal{M}_7$ supporting Contact 3-Structures (C3S) that induce a ``transverse'' $SU(3)$-structure. We prove that this induced structure belongs to the symplectic nearly half-flat (S(nearly)HF) class: $dω_Φ=0$ exactly, while $dΩ_+$ is suppressed as $\mathcal{O}(e^{-N^{1/3}/\mathcal{O}(1)})$ in the infrared "MQGP limit", leaving $W_Φ^{SU(3)}=W_2^-$ as the sole non-vanishing Chiossi--Salamon torsion class and completing the $G$-structure classification of the MQGP dual initiated in arXiv:1507.02692,2004.07259, 2211.13186. As a physical application, Kaluza--Klein reduction of the eleven-dimensional Hodge dual of the differential of the $G_2$-structure positive three-form on $\mathcal{M}_7$, organised through the $G_2$/S(nearly)HF torsion data, yields a radial ``magnetic field'' $\mathcal{B}_{\rm KK}(r)$ whose squared norm factorises exactly into external and internal factors. $\mathcal{B}_{\rm KK}(r)$ satisfies a Bessel-type ODE with a regular singular point at the horizon; normalisability and infrared regularity select $J_2$, with harmonicity of the aforementioned internal factor recovered from the large-$N$ suppression. $\mathcal{B}_{\rm KK}$ is related to the magnetic field of the type~IIA flavour $D6$-branes via a non-linear power law, furnishing a top-down holographic mechanism for generating weak magnetic fields in finite-temperature string theory.

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arXiv2025

$T_c$, Photoproduction, Paramagnetic Anisotropic Plasma, IR Log-Gravitational-DBI Renormalization and $G_2$-Structure Induced (Almost) Contact 3-Structures in Hot Strongly Magnetic MQCD at Intermediate Coupling

After obtaining the flavor $D6$-brane gauge fields/their fluctuations in the type IIA dual of T>T_c QCD-like theories at intermediate coupling (via the ${\cal M}$-theory uplift's ${\cal O}(R^4)$ corrections) in the absence/presence of a strong magnetic field, we compute the photoproduction spectral function and get a nice agreement with gauged supergravity backgrounds arXiv:2204.00024 [hep-th]. We demonstrate from the EoS that the holographic dual, in principle, could correspond to several $T>T_c$ scenarios: anisotropic paramagnetic plasma transitioning via a smooth crossover to exotic matter as the universe cools, the stable wormhole, and a paramagnetic pressure/energy-anisotropic plasma. Given that $T>T_c$ QGP is expected to be paramagnetic, see Bali et al '14, the third possibility appears to be the preferred one. We also show that it is not possible that the anisotropic plasma leads to the formation of a compact star. IR renormalization of the DBI action requires a boundary Log-det-Ricci-tensor counter term. {\it Noting (i) photoproduction spectral function determined from gauge field fluctuations receiving ${\cal O}(R^4)$-corrections, if complexified, include a non-analytic-complexified gauge-coupling dependence, and correspond to Contact 3-Structures; (ii) pressure/energy density, etc. determined from world-volume gauge fields and not ${\cal O}(R^4)$-corrected, if complexified, are analytic in the complexified gauge coupling, and correspond to Almost Contact 3-Structures (AC3S) both induced from the $G_2$ structure of a closed seven-fold, we conjecture (i) the lack of $N$-path connectedness in the parameter space associated with AC3S and C3S arXiv:2211.13186[hep-th] to be equivalent to that gauge field fluctuations can not be finite, and (zero-instanton sector) ${\cal O}(R^4)$ non-renormalized gauge fields produce ${\cal O}(R^4)$-corrected gauge fluctuation; (ii) C3S--UV--> AC3S.

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arXiv2025

On the Ubiquity of (Almost) Contact Structures in Hot MQCD at Intermediate Coupling

Relevant to top-down ${\cal M}$-theory dual of large-$N$ thermal QCD-like theories at intermediate coupling, induced by the $G_2$ structure supported by the closed $M_7$ - a warped product of the ${\cal M}$-theory circle and a non-Kähler six-fold which is the warped product of the thermal circle with a non-Einsteinian deformation of $T^{1,1}$ - we obtain explicitly (Almost) Contact (3) (Metric)Structure(s) and a three-tuple of $SU(3)$ structures along the "transverse" six-fold induced by the AC(3)MS on $M_7$. A novel result in this context is that in the Infra-Red, within the parameter space of AC3S arising from G2 structures, the subspaces of C3S and AC3S are not mutually "N-path connected". Relevance of the results to staying out of the non-supersymmetric swampland, entanglement entropy of eternal black holes, chaos, bulk-to-shear viscosity ratio $\fracζη$, paramagnetic plasma EoS and photoproduction in a strong magnetic field, in the context of top-down holographic thermal QCD at intermediate coupling, is highlighted/reiterated.

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arXiv2024

Bulk Viscosity, Speed of Sound and Contact Structure at Intermediate Coupling

In the context of strongly coupled thermal QCD-like theories, the bulk viscosity($ζ$)-to-shear viscosity($η$) ratio using the type IIA-theory dual of thermal QCD-like theories was shown to vary like $\frac{1}{3} - c_s^2$ (arXiv:1807.04713) ($c_s$ being the speed of sound), and the same ($\fracζη$) at weak coupling using kinetic theory and finite temperature field theory, was shown and is known to vary like $\left(\frac{1}{3} - c_s^2\right)^2$ (arXiv:1807.04713). The novelties of the results of this paper are that we not only show for the first time from ${\cal M}$ theory that at intermediate coupling, with the inclusion of the ${\cal O}(R^4)$ corrections, the result obtained for $\fracζη$ interpolates between the strong and weak coupling results in a way consistent with lattice computations of $SU(3)$ Gluodynamics (arXiv:0710.3717 [hep-lat]) within statistical errors (and within the temperature range permissible by our ${\cal M}$-theory uplift), but also observe that this behavior is related to the existence of Contact 3-Structures that exist only at intermediate coupling effected by the intermediate-$N$ "MQGP" limit of (arXiv:2211.13186[hep-th]). We also obtain an explicit dependence of $\fracζη$ on (fractional powers of) the temperature-dependent/running gauge coupling (and its temperature derivative), and verify that the weak-coupling result dominates at large temperatures. We further conjecture that the aforementioned fractional-power-dependence of $\fracζη$ on the gauge coupling is related to the lack of ``$N$-connectedness'' in the parameter space of Contact 3-Structures (as shown in arXiv:2211.13186[hep-th]).

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arXiv2024

On ${\cal M}$-Theory Dual of Large-$N$ Thermal QCD-Like Theories up to ${\cal O}(R^4)$ and $G$-Structure Classification of Underlying Non-Supersymmetric Geometries

Construction of a top-down holographic dual of thermal QCD-like theories (equivalence class of theories which are UV-conformal, IR-confining and have fundamental quarks) {\it at intermediate 't Hooft coupling} and the $G$-structure (torsion classes) classification of the underlying geometries (in the Infra Red (IR)/non-conformal sector in particular) of the {\it non-supersymmetric} string/${\cal M}$-theory duals, have been missing in the literature. We take the first important steps in this direction by studying the ${\cal M}$ theory dual of large-$N$ thermal QCD-like theories at intermediate gauge and 't Hooft couplings and obtaining the ${\cal O}(l_p^6)$ corrections arising from the ${\cal O}(R^4)$ terms to the "MQGP" background (${\cal M}$-theory dual of large-$N$ thermal QCD-like theories at intermediate gauge/string coupling, but large 't Hooft coupling) of \cite{MQGP}. The main Physics lesson learnt is that there is a competition between non-conformal IR enhancement and Planckian and large-$N$ suppression and going to orders beyond the ${\cal O}(l_p^6)$ is necessitated if the IR enhancement wins out. The main lesson learnt in Math is in the context of the differential geometry ($G$-structure classification) of the internal manifolds relevant to the string/${\cal M}$-theory duals of large-$N$ thermal QCD-like theories, wherein we obtain for the first time inclusive of the ${\cal O}(R^4)$ corrections in the Infra-Red (IR), the $SU(3)$-structure torsion classes of the type IIA mirror of \cite{metrics} (making contact en route with Siegel theta functions related to appropriate hyperelliptic curves, as well as the Kiepert's algorithm of solving quintics), and the $G_2/SU(4)/Spin(7)$-structure torsion classes of the seven- and eight-folds associated with its ${\cal M}$ theory uplift.

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arXiv2024

QCD-Compatible Supermassive Inert Top-Down Holographic Mesinos at Intermediate Coupling

A longstanding problem with the popular Sakai-Sugimoto holographic dual of thermal QCD is that the "mesinos", the (non-supersymmetric) fermionic partners of the mesons, are nearly isospectral with mesons and have an unsuppressed mesino-meson interaction, both being in contradiction with actual QCD. We solve this problem in a UV-complete (and ${\it different}$) type IIA string dual ${\it at\ intermediate\ coupling}$ of realistic thermal QCD, in which the mesinos are shown to be much heavier than and non-interacting with mesons (the wave-function/mass/interaction terms receiving no ${\cal M}$-theory ${\cal O}(R^4)$ corrections). In particular we derive a large-$N$ enhancement of the KK mass scale $M_{KK}$ (from $M_{KK}$ to $M_{KK}^{\rm eff}\sim N^{1 + \frac{1}{{\cal O}(1)}}M_{KK}$) arising from the construction of the type IIA mirror \cite{MQGP} of the type IIB dual \cite{metrics} of thermal QCD-like theories, as well as the generation of a one-parameter family of $M_{KK}$-independent mass scale at ${\cal O}(R^4)$ in the ${\cal M}$-theory uplift \cite{OR4} wherein the parameter can be made appropriately large. We also show that the mesino-mesino-single-($ρ/π$)meson interactions, vanish identically in the aforementioned type IIA holographic dual.

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arXiv2024

Pole-Skipping and Chaos in Hot ${\cal M}$QCD

We address the question of whether thermal QCD at high temperature is chaotic from the ${\cal M}$ theory dual of QCD-like theories at intermediate coupling as constructed in arXiv: 2004.07259. The equations of motion of the gauge-invariant combination $Z_s(r)$ of scalar metric perturbations is shown to possess an irregular singular point at the horizon radius $r_h$. Very interestingly, at a specific value of the imaginary frequency and momentum used to read off the analogs of the ''Lyapunov exponent'' $λ_L$ and ''butterfly velocity'' $v_b$ not only does $r_h$ become a regular singular point, but truncating the incoming mode solution of $Z_s(r)$ as a power series around $r_h$, yields a ''missing pole'', i.e., $C_{n, n+1}=0,\ {\rm det}\ M^{(n)}=0, n\in\mathbb{Z}^+$ is satisfied for a single $n\geq3$ depending on the values of the string coupling $g_s$, number of (fractional) $D3$ branes $(M)N$ and flavor $D7$-branes $N_f$ in the parent type IIB set (arXiv:hep-th/0902.1540), e.g., for the QCD(EW-scale)-inspired $N=100, M=N_f=3, g_s=0.1$, one finds a missing pole at $n=3$. For integral $n>3$, truncating $Z_s(r)$ at ${\cal O}((r-r_h)^n)$, yields $C_{n, n+1}=0$ at order $n,\ \forall n\geq3$. Incredibly, (assuming preservation of isotropy in $\mathbb{R}^3$ even with the inclusion of higher derivative corrections) the aforementioned gauge-invariant combination of scalar metric perturbations receives no ${\cal O}(R^4)$ corrections. Hence, (the aforementioned analogs of) $λ_L, v_b$ are unrenormalized up to ${\cal O}(R^4)$ in ${\cal M}$ theory.

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arXiv2023

Entanglement entropy and Page curve from the ${\cal M}$-theory dual of thermal QCD above $T_c$ at intermediate coupling

Obtaining the Page curve in the context of eternal black holes associated with top-down non-conformal holographic thermal duals at intermediate coupling, has been entirely unexplored in the literature. We fill this gap in the context of a doubly holographic setup relevant to the M-theory dual of thermal QCD-like theories at $T>T_c$ at intermediate coupling. Remarkably, excluding the higher derivative terms, the entanglement entropy(EE) of the Hawking radiation from the on-shell Wald EE (for appropriate choices of constants of integration appearing in the embeddings) increases almost linearly with the boundary time due to dominance of EE contribution from the Hartman-Maldacena(HM)-like surface $S_{EE}^{HM, β^0}, β\sim l_p^6$. Curiously, this imparts a "Swiss-Cheese" structure to the surface $S_{EE}^{HM, β^0}$ at a given time (less than the Page time $t_{P}$), in $\mathbb{R}_{\geq0} \times \mathbb{C}$ effecting what could be dubbed as a "Large N Scenario" (LNS). Then, after $t_{P}$, the EE contribution from the Island Surface (IS) $S_{EE}^{IS, β^0}$ dominates and saturates the linear time growth of the EE of Hawking radiation and leads to the Page curve. Requiring $S_{EE}^{IS, β^0}/S_{BH}\sim2$ up to LO in the non-conformal analog of "$c G_N^{(11)}/r_h^9$", and positivity of $t_{P}$, set respectively a lower and upper bound on the horizon radius $r_h$ (the non-extremality parameter). With the inclusion of the $O(R^4)$ terms in M theory, the turning point associated with the HM-like surface/IS being in the deep IR, results in a relationship between $l_p$ and $r_h$ along with a conjectural $e^{-{\cal O}(1) N^{1/3}}$-suppression (motivated by $S_{EE}^{IS, β^0}/S_{BH}\sim2$). We obtain a hierarchy with respect to this N-dependent exponential in $S_{EE}^{HM, β^0}, S_{EE}^{IS, β^0} (O(β^0))$ and $S_{EE}^{HM, β}, S_{EE}^{HM, β} (O(β))$.

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arXiv2022

${\mathscr {M}}$cTEQ (${\mathscr {M}}$ ${\bf c}$hiral perturbation theory-compatible deconfinement ${\bf T}$emperature and ${\bf E}$ntanglement Entropy up to terms ${\bf Q}$uartic in curvature) and FM (${\bf F}$lavor ${\bf M}$emory)

A holographic computation of $T_c$ at ${\it intermediate\ coupling}$ from M-theory dual of thermal QCD-like theories, has been missing in the literature. Filling this gap, we demonstrate a novel UV-IR mixing, (conjecture and provide evidence for) a non-renormalization beyond 1 loop of ${\bf M}-{\bf c}$hiral perturbation theory arXiv:2011.04660[hep-th]-compatible deconfinement ${\bf T}$emperature, and show equivalence with an ${\bf E}$ntanglement (as well as Wald) entropy arXiv:0709.2140[hep-th] computation, up to terms ${\bf Q}$uartic in curvature. We demonstrate a ${\bf F}$lavor-${\bf M}$emory (FM) effect in the M-theory uplifts of the gravity duals, wherein the no-braner M-theory uplift retains the "memory" of the flavor D7-branes of the parent type IIB dual in the sense that a specific combination of the aforementioned quartic corrections to the metric components precisely along the compact part of the non-compact four-cycle "wrapped" by the flavor D7-branes, is what determines, e.g., the Einstein-Hilbert action at O$(R^4)$. The same linear combination of O$(R^4)$ metric corrections, upon matching the phenomenological value of the coupling constant of one of the SU(3) NLO ChPT Lagrangian, is required to have a definite sign. Interestingly, in the decompactification limit of the spatial circle, we ${\it derive}$ this, and obtain the values of the relevant O$(R^4)$ metric corrections. Further, equivalence with Wald entropy for the black hole at ${\cal O}(R^4)$ imposes a linear constraint on the same linear combination of metric corrections. Remarkably, when evaluating $T_c$ from an entanglement entropy computation in the thermal gravity dual, due to a delicate cancelation between the ${\cal O}(R^4)$ corrections from a subset of the abovementioned metric components, one sees that there are no corrections to $T_c$ at quartic order supporting the conjecture referred to above.

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arXiv2021

(Phenomenology/Lattice-Compatible) $SU(3)$ M$χ$PT HD up to ${\cal O}(p^4)$ and the ${\cal O}\left(R^4\right)$-Large-$N$ Connection

Obtaining the values of the coupling constants of the low energy effective theory corresponding to QCD, compatible with experimental data, even in the (vector) mesonic sector from (the ${\cal M}$-theory uplift of) a UV-complete string theory dual, has thus far been missing in the literature. We take the first step in this direction by obtaining the values of the coupling constants of the ${\cal O}(p^4)$ $χ$PT Lagrangian in the chiral limit involving the NGBs and $ρ$ meson (and its flavor partners) from the ${\cal M}$-theory /type IIA dual of large-$N$ thermal QCD, inclusive of the ${\cal O}(R^4)$ corrections. We observe that ensuring compatibility with phenomenological/lattice results (the values ) as given in arXiv:1510.01634[hep-ph], requires a relationship relating the ${\cal O}(R^4)$ corrections and large-$N$ suppression. In other words, QCD demands that the higher derivative corrections and the large-$N$ suppressed corrections in its M/string theory dual are related. As a bonus, we explicitly show that the ${\cal O}(R^4)$ corrections in the UV to the ${\cal M}$-theory uplift of the type IIB dual of large-$N$ thermal QCD, can be consistently set to be vanishingly small.

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arXiv2020

The QCD Trace Anomaly at Strong Coupling from M-Theory

In this short note we address the issue of obtaining the temperature dependence of the QCD conformal anomaly from a top-down holographic dual consistent with very recent lattice results for both, T Tc. As the holographic dual, we use the M-theory uplift of the SYZ type IIA mirror obtained in arXiv:1306.4339 at finite gauge/string coupling (as part of the 'MQGP' limit) of the type IIB holographic dual of large-N thermal QCD of arXiv:0902.1540. We also show that after a tuning of the (small) Ouyang embedding parameter and radius of a blown-up S^2 when expressed in terms of the horizon radius, a QCD deconfinement temperature Tc = 150 MeV from a Hawking-Page phase transition at vanishing baryon chemical potential, consistent with lattice QCD in the heavy-quark limit, can be obtained.

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arXiv2019

Bulk Viscosity at Extreme Limits: From Kinetic Theory to Strings

In this paper we study bulk viscosity in a thermal QCD model with large number of colors at two extreme limits: the very weak and the very strong 't Hooft couplings. The weak coupling scenario is based on kinetic theory, and one may go to the very strong coupling dynamics via an intermediate coupling regime. Although the former has a clear description in terms of kinetic theory, the intermediate coupling regime, which uses lattice results, suffers from usual technical challenges that render an explicit determination of bulk viscosity somewhat difficult. On the other hand, the very strong 't Hooft coupling dynamics may be studied using string theories at both weak and strong string couplings using gravity duals in type IIB as well as M-theory respectively. In type IIB we provide the precise fluctuation modes of the metric in the gravity dual responsible for bulk viscosity, compute the speed of sound in the medium and analyze the ratio of the bulk to shear viscosities. In M-theory, where we uplift the type IIA mirror dual of the UV complete type IIB model, we study and compare both the bulk viscosity and the sound speed by analyzing the quasi-normal modes in the system at strong IIA string coupling. By deriving the spectral function, we show the consistency of our results both for the actual values of the parameters involved as well for the bound on the ratio of bulk to shear viscosities.

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arXiv2018

M-Theory Exotic Scalar Glueball Decays to Mesons at Finite Coupling

Using the pull-back of the perturbed type IIA metric corresponding to the perturbation of arXiv:hep-th/1306.4339's M-theory uplift of arXiv:hep-th/0902.1540's UV-complete top-down type IIB holographic dual of large-$N$ thermal QCD, at finite coupling, we obtain the interaction Lagrangian corresponding to exotic scalar glueball($G_E$)-$ρ/π$-meson interaction, linear in the exotic scalar glueball and up to quartic order in the $π$ mesons. In the Lagrangian, the coupling constants are determined as (radial integrals of) arXiv:hep-th/1306.4339's M-theory uplift's metric components and six radial functions appearing in the M-theory metric perturbations. Assuming $M_G>2M_ρ$, we then compute $ρ\rightarrow2π, G_E\rightarrow2π, 2ρ, ρ+2π$ decay widths as well as the direct and indirect (mediated via $ρ$ mesons) $G_E\rightarrow4π$ decays. For numerics, we choose $f0[1710]$ and compare with previous calculations. We emphasize that our results can be made to match PDG data (and improvements thereof) exactly by appropriate tuning of some constants of integration appearing in the solution of the M-theory metric perturbations and the $ρ$ and $π$ meson radial profile functions - a flexibility that our calculations permits.

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arXiv2018

On Bulk Viscosity at Weak and Strong 't Hooft Couplings

Bulk viscosity is an important transport coefficient that exists in the hydrodynamical limit only when the underlying theory is non-conformal. One example being thermal QCD with large number of colors. We study bulk viscosity in such a theory at low energies and at weak and strong 't Hooft couplings when the temperature is above the deconfinement temperature. The weak coupling analysis is based on Boltzmann equation from kinetic theory whereas the strong coupling analysis uses non-conformal holographic techniques from string and M-theories. Using these, many properties associated with bulk viscosity may be explicitly derived. This is a shortened companion paper that summarizes some of the results of our longer paper arXiv:1807.04713.

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arXiv2017

Delocalized SYZ Mirrors and Confronting Top-Down $SU(3)$-Structure Holographic Meson Masses at Finite $g$ and $N_c$ with P(article) D(ata) G(roup) Values

Meson spectroscopy at finite gauge coupling - whereat any perturbative QCD computation would break down - and finite number of colors, from a top-down holographic string model, has thus far been entirely missing in the literature. This paper fills in this gap. Using the delocalized type IIA SYZ mirror (with $SU(3)$ structure) of the holographic type IIB dual of large-$N$ thermal QCD of arXiv:hep-th/0902.1540 as constructed in arXiv:hep-th/1306.4339 at finite coupling and number of colors ($N_c$ = Number of $D5(\overline{D5}$)-branes wrapping a vanishing two-cycle in the top-down holographic construct of arXiv:hep-th/0902.1540 = ${\cal O}(1)$ in the IR in the MQGP limit of arXiv:hep-th/1306.4339 at the end of a Seiberg duality cascade), we obtain analytical (not just numerical) expressions for the vector and scalar meson spectra and compare our results with previous calculations of hep-th/0412141, arXiv:1409.0559 [hep-th], and obtain a closer match with the Particle Data Group (PDG) results (Chin. Phys. C, 38, 090001 (2014) and 2015 update). Through explicit computations, we verify that the vector and scalar meson spectra obtained by the gravity dual with a black hole for all temperatures (small and large) are nearly isospectral with the spectra obtained by a thermal gravity dual valid for only low temperatures; the isospectrality is much closer for vector mesons than scalar mesons. The black hole gravity dual (with a horizon radius smaller than the deconfinement scale) also provides the expected large-$N$ suppressed decrease in vector meson mass with an increase of temperature.

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arXiv2017

Top-Down Holographic $G$-Structure Glueball Spectroscopy at (N)LO in $N$ and Finite Gauge Coupling

The top-down type IIB holographic dual of large-$N$ thermal QCD as constructed in arXiv:0902.1540 involving a fluxed resolved warped deformed conifold, its delocalized type IIA SYZ mirror as well as its M-theory uplift constructed in arXiv:1306.4339 - both in the finite gauge coupling ($g_s\stackrel{<}{\sim}1$)/`MQGP' limit of arXiv:1306.4339 - were shown explicitly to possess a local $SU(3)/G_2$-structure in arXiv:1507.02692 Glueball spectroscopy at finite gauge coupling has thus far been missing in the literature. In this paper, we fill this gap by calculating the masses of the $0^{++}, 0^{-+},0^{--}, 1^{++}, 2^{++}$ (`glueball') states (which correspond to fluctuations in the dilaton or complexified two-forms or appropriate metric components) in the aforementioned backgrounds of $G$-structure in the `MQGP' limit of arXiv:1306.4339, using WKB quantization conditions on one hand and imposing Neumann/Dirichlet boundary conditions at an IR cut-off/horizon radius $r_h$ on the solutions to the equations of motion on the other. We also discuss $r_h=0$-limits of all calculations; in this context we also calculate the $0^{++}, 0^{--},1^{++}, 2^{++}$ glueball masses up to NLO in $N$ and find a $\frac{g_sM^2}{N}(g_sN_f)$-suppression similar to and further validating a similar semi-universality of NLO corrections to transport coefficients, observed in arXiv:1606.04949.

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arXiv2016

New Insights into Properties of Large-N Holographic Thermal QCD at Finite Gauge Coupling at (the Non-Conformal/Next-to) Leading Order in N

In the context of [1]'s string theoretic dual of large-N thermal QCD-like theories at finite gauge/string coupling (as part of the `MQGP' limit of [2]), we discuss the following. First, up to LO in N, using the results of [3], we show that the local T^3 of [2] is the T^2-invariant sLag of [3] in a resolved conifold. This, together with the results of [4], shows that for a (predominantly resolved or deformed) resolved warped deformed conifold, the local T^3 of [2] in the MQGP limit, is the T^2-invariant sLag of [3] justifying the construction of the delocalized SYZ type IIA mirror of the type IIB background of [1]. Then, using the prescription of [5], we obtain the temperature dependence of the thermal (and electrical) conductivity working up to leading order in N (the number of D3-branes), and upon comparison with [6] show that the results mimic a 1+1-dimensional Luttinger liquid with impurities. Further, including sub-leading non-conformal terms in the metric determined by M (the number of fractional D-branes = the number of colors = 3 in the IR after the end of a Seiberg duality cascade), by looking at respectively the scalar, vector and tensor modes of metric perturbations and using [7]'s prescription of constructing appropriate gauge-invariant perturbations, we obtain respectively the speed of sound, the diffusion constant and the shear viscosity η(and η/s) including the non-conformal O((g_s M^2) (g_s N_f)/N<<1)-corrections, N_f being the number of flavor D7-branes.

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arXiv2016

On Aspects of Holographic Thermal QCD at Finite Coupling

Some Physics (obtaining lattice-compatible deconfinement temperature, some transport coefficients and Einstein's relation) and Mathematics (torsion classes and supersymmetry) issues pertaining to the delocalized SYZ type IIA mirror of [1] and its M theory uplift in the MQGP limit of [2], are discussed.

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