Robert B. Mann

University of Waterloo | UWaterloo · Department of Physics and Astronomy

We develop a novel holographic dictionary for the thermodynamics of black holes with Lifshitz and hyperscaling violating asymptotics, generalizing the dictionary for Anti-de Sitter black holes. Using our dictionary we show that the holographic Euler equation is dual to a generalized Smarr formula for these black holes, and we find a precise match b...

In this work, we investigate the universal classifications of black hole states by considering them as topological defects within the thermodynamic parameter space. Through the asymptotic behaviors of the constructed vector, our results indicate the existence of four distinct topological classifications, denoted as $W^{1-}$, $W^{0+}$, $W^{0-}$, and...

We consider the problem of extracting tripartite entanglement through single local instantaneous interactions of a separable target system A−B−C with a scalar field. We find, nonperturbatively, that tripartite entanglement is easily extracted in this scenario, in strong contrast to bipartite extraction, which is not possible due to a no-go theorem....

We study Unruh phenomena for a qudit detector coupled to a quantized scalar field, comparing its response to that of a standard qubit-based Unruh-DeWitt detector. We show that there are limitations to the utility of the detailed balance condition as an indicator for Unruh thermality of higher-dimensional qudit detector models. This can be traced to...

We investigate the correlation harvesting protocol using two Unruh-DeWitt particle detectors moving along four classes of uniformly accelerated trajectories categorized by Letaw: linear, catenary, cusped, and circular motions. For each trajectory, two types of configurations are carried out: one possesses a stationary (time-translation invariant) W...

Unique features of particle orbits produce novel signatures of gravitational observable phenomena and are quite useful in testing compact astrophysical objects in general relativity or modified theories of gravity. Here we observe a representative example that a static, spherically symmetric black hole solution with nonlinear electrodynamics admits...

We consider a quantum Otto engine using an Unruh-DeWitt particle detector model which interacts with a quantum scalar field in curved spacetime. We express a generic condition for extracting positive work in terms of the effective temperature of the detector. This condition reduces to the well-known positive work condition in the literature under t...

A bstract Employing the novel exact dictionary between the laws of extended black hole thermodynamics and the laws of the dual CFT, we study the extended thermodynamics for CFT states that are dual to neutral singly-spinning asymptotically AdS black holes in d bulk spacetime dimensions. On the field theory side we include two independent pairs of t...

We investigate the correlation harvesting protocol using two Unruh-DeWitt particle detectors moving along four classes of uniformly accelerated trajectories categorized by Letaw: linear, catenary, cusped, and circular motions. For each trajectory, two types of configurations are carried out: one possesses a stationary (time-translation invariant) W...

The first investigation of tripartite entanglement harvesting in the vicinity of a black hole is carried out. Working in the context of a static Bañados–Teitelboim–Zanelli (BTZ) black hole spacetime the authors find that it is possible to harvest tripartite entanglement in regions where harvesting of bipartite entanglement is known to be impossible...

The Majorana stellar representation is used to characterize spin states that have a maximally negative Wigner quasiprobability distribution on a spherical phase space. These maximally Wigner-negative spin states generally exhibit a partial but not high degree of symmetry within their star configurations. In particular, for spin j > 2, maximal const...

We consider two initially entangled Unruh-DeWitt particle detectors and examine how the initial entanglement changes after interacting with a quantum scalar field. Just as initially separable detectors can extract entanglement from the field, entangled detectors also can gain more entanglement so long as they are weakly correlated at the beginning....

Employing the novel exact dictionary between the laws of extended black hole thermodynamics and the laws of the dual CFT, we study the extended thermodynamics for CFT states that are dual to neutral singly-spinning asymptotically AdS black holes in $d$ bulk spacetime dimensions. On the field theory side we include two independent pairs of thermodyn...

By respecting the conformal symmetry of the dual conformal field theory, and treating the conformal factor of the Anti-de Sitter boundary as a thermodynamic parameter, we formulate the holographic first law that is exactly dual to the first law of extended black hole thermodynamics with variable cosmological constant but fixed Newton’s constant.

We carry out the first investigation of tripartite entanglement harvesting in the vicinity of a black hole. Working in the context of a static BTZ black hole spacetime we find that it is possible to harvest tripartite entanglement in regions where harvesting of bipartite entanglement is known to be impossible due to intense Hawking radiation. In th...

We investigate the mutual information harvesting protocol for two uniformly accelerated particle detectors. We numerically show that, while a single detector responds as if it is immersed in a thermal bath, the quantum mutual information between two accelerating detectors behaves differently than that of two inertial detectors in a thermal bath. Th...

A bstract The Eguchi-Hanson-AdS 5 family of spacetimes are a class of static, geodesically complete asymptotically locally AdS 5 soliton solutions of the vacuum Einstein equations with negative cosmological constant. They have negative mass and are parameterized by an integer p ≥ 3 with a conformal boundary with spatial topology L ( p, 1). We inves...

Unique features of particle orbits would produce novel signatures of gravitational observable phenomena, and are quite useful in testing compact astrophysical objects in general relativity or modified theories of gravity. In this work, we observe a representative example that static, spherically symmetric dyonic black hole solution admit static poi...

An isolated critical point is a peculiar thermodynamic critical point that occurs in the phase diagram of hyperbolic black holes in Kth-order Lovelock gravity in higher dimensions (with K odd) for special tuned Lovelock coupling constants. It corresponds to a “merger” of two swallowtails and is characterized by nonstandard critical exponents. Upon...

By respecting the conformal symmetry of the dual CFT, and treating the conformal factor of the AdS boundary as a dynamical variable, we formulate the holographic first law that is exactly dual to the first law of extended black hole thermodynamics with variable cosmological constant but fixed Newton's constant.

The Eguchi-Hanson-AdS$_5$ family of spacetimes are a class of static, geodesically complete asymptotically locally AdS$_5$ soliton solutions of the vacuum Einstein equations with negative cosmological constant. They have negative mass and are parameterized by an integer $p\geq 3$ with a conformal boundary with spatial topology $L(p,1)$. We investig...

We consider two initially entangled Unruh-DeWitt particle detectors and examine how the initial entanglement changes after interacting with a quantum scalar field. As initially nonentangled detectors extract entanglement from the field, entangled detectors also can gain more entanglement so long as they are weakly correlated at the beginning. For i...

We investigate the mutual information harvesting protocol for two uniformly accelerated particle detectors. We numerically show that, while a single detector responds as if it is immersed in a thermal bath, the quantum mutual information between two accelerating detectors behaves differently than that of two inertial detectors in a thermal bath. Th...

In this Letter, employing the generalized off-shell free energy, we treat black hole solutions as defects in the thermodynamic parameter space. The results show that the positive and negative winding numbers corresponding to the defects indicate the local thermodynamical stable and unstable black hole solutions, respectively. The topological number...

A bstract We study the holographic dual of the extended thermodynamics of spherically symmetric, charged AdS black holes in the context of the AdS/CFT correspondence. The gravitational thermodynamics of AdS black holes can be extended by allowing for variations of the cosmological constant and Newton’s constant. In the dual CFT this corresponds to...

We analyze a tripartite entanglement harvesting protocol with three Unruh-DeWitt detectors adiabatically interacting with a quantum scalar field in \((3+1)\)-dimensional Minkowski spacetime. We consider linear, equilateral triangular, and scalene triangular configurations for the detectors, all of which remain static. We find that, under the same p...

In this work, employing the generalized off-shell free energy, we treat black hole solutions as defects in the thermodynamic parameter space. The results show that the positive and negative winding numbers corresponding to the defects indicate the local thermodynamical stable and unstable black hole solutions, respectively. The topological number $...

We investigate the correlation harvesting protocol for mutual information between two Unruh-DeWitt detectors in a static Bañados-Teitelboim-Zanelli black hole spacetime. Here, the effects coming from communication and change in proper separation of the detectors are set to be negligible so that only a black hole affects the extracted mutual informa...

The information loss paradox is widely regarded as one of the biggest open problems in theoretical physics. Several classical and quantum features must be present to enable its formulation. First, an event horizon is needed to justify the objective status of tracing out degrees of freedom inside the black hole. Second, evaporation must be completed...

The Majorana stellar representation is used to characterize spin states that have a maximally negative Wigner quasiprobability distribution on a spherical phase space. These maximally Wigner-negative spin states generally exhibit a partial but not high degree of symmetry within their star configurations. In particular, for spin $j > 2$, maximal con...

We investigate the correlation harvesting protocol for mutual information between two Unruh-DeWitt detectors in a static BTZ black hole spacetime. Here, the effects coming from communication and change in proper separation of the detectors are set to be negligible so that only a black hole affects the extracted mutual information. We find that, unl...

A bstract The Lense-Thirring spacetime describes a 4-dimensional slowly rotating approximate solution of vacuum Einstein equations valid to a linear order in rotation parameter. It is fully characterized by a single metric function of the corresponding static (Schwarzschild) solution. In this paper, we introduce a generalization of the Lense-Thirri...

A bstract We study the dynamics of an Unruh-DeWitt detector interacting with a massless scalar field in an arbitrary static spherically symmetric spacetimes whose metric is characterised by a single metric function f ( r ). In order to obtain clean physical insights, we employ the derivative coupling variant of the Unruh-DeWitt model in (1+1) dimen...

One consequence of the cosmic censorship conjecture is that any topological structure will ultimately collapse to within the horizons of a set of black holes, and as a result, an external classical observer will be unable to probe it. However, a single two-level quantum system [Unruh–DeWitt (UDW) detector] that remains outside of the horizon has be...

We study the dynamics of an Unruh-DeWitt detector interacting with a mass-less scalar field in an arbitrary static spherically symmetric spacetimes whose metric is characterised by a single metric function f (r). In order to obtain clean physical insights, we employ the derivative coupling variant of the Unruh-DeWitt model in (1+1) dimensions where...

We study the hololgraphic dual of the extended thermodynamics of spherically symmetric, charged AdS black holes in the context of the AdS/CFT correspondence. The gravitational thermodynamics of AdS black holes can be extended by allowing for variations of the cosmological constant and Newton's constant. In the dual CFT this corresponds to including...

We investigate how entangled inertial Unruh-DeWitt detectors are affected by interaction with a quantum field using a nonperturbative method. Inertial detectors in a (3+1)-dimensional Minkowski spacetime with instantaneous switching (δ-switching) experience degradation of their initial entanglement as their coupling strength with a scalar field inc...

The Lense--Thirring spacetime describes a 4-dimensional slowly rotating approximate solution of vacuum Einstein equations valid to a linear order in rotation parameter. It is fully characterized by a single metric function of the corresponding static (Schwarzschild) solution. In this paper, we introduce a generalization of the Lense--Thirring space...

For distant observers black holes are trapped spacetime domains bounded by apparent horizons. We review properties of the near-horizon geometry emphasizing the consequences of two common implicit assumptions of semiclassical physics. The first is a consequence of the cosmic censorship conjecture, namely that curvature scalars are finite at apparent...

We investigate thermodynamic aspects of black holes in the recently formulated four-dimensional Gauss-Bonnet theory of gravity, focusing on its asymptotically de Sitter (Λ>0) solutions. We take a Euclidean path integral approach, where thermodynamic data is fixed at a finite radius “cavity” outside the black hole to achieve equilibrium in the prese...

The information loss paradox is widely regarded as one of the biggest open problems in theoretical physics. Several classical and quantum features must be present to enable its formulation. First, an event horizon is needed to justify the objective status of tracing out degrees of freedom inside the black hole. Second, evaporation must be completed...

We investigate how entangled inertial Unruh-DeWitt detectors are affected by interaction with a quantum field using a nonperturbative methods. Inertial detectors in a $(3+1)$-dimensional Minkowski spacetime with instantaneous switching ($\delta$-switching) experience degradation of their initial entanglement as their coupling strength with a scalar...

We reconsider the thermodynamics of anti–de Sitter black holes in the context of gauge-gravity duality. In this new setting, where both the cosmological constant Λ and the gravitational Newton’s constant G are varied in the bulk, we rewrite the first law in a new form containing both Λ (associated with thermodynamic pressure) and the central charge...

Ruppeiner geometry has been found to be a novel promising approach to uncover the microstructure of fluid systems and black holes. In this work, combining with the micro model of the Van der Waals fluid, we shall propose a first microscopic interpretation for the empirical observation of Ruppeiner geometry. Then employing the microscopic interpreta...

The nonclassicality of simple spin systems as measured by Wigner negativity is studied on a spherical phase space. Several SU(2)-covariant states with common qubit representations are analyzed: spin coherent states, spin cat (Greenberger-Horne-Zeilinger or N00N) states, and Dicke (W) states. We derive a bound on the Wigner negativity of spin cat st...

We investigate thermodynamic aspects of black holes in the recently formulated four dimensional Gauss-Bonnet theory of gravity, focusing on its asymptotically de Sitter ($\Lambda>0$) solutions. We take a Euclidean path integral approach, where thermodynamic data is fixed at a finite radius `cavity' outside the black hole to achieve equilibrium in t...

Understanding the dynamic process of black hole thermodynamic phase transitions at a triple point is a huge challenge. In this paper, we conduct the first investigation of dynamic phase behavior at a black hole triple point. By numerically solving the Smoluchowski equation near the triple point for a six-dimensional charged Gauss-Bonnet anti-de Sit...

We carry out the first investigation of the entanglement and mutual information harvesting protocols for detectors freely falling into a black hole. Working in (1+1)-dimensional Schwarzschild black hole spacetime, we consider two pointlike Unruh-DeWitt detectors in different combinations of free-falling and static trajectories. Employing a generali...

We investigate the sensitivity of an Unruh–DeWitt detector to the global features of a deficit angle that are otherwise classically inaccessible. Specifically, we consider a detector placed inside an infinite thin hollow cylinder whose spacetime is everywhere flat but outside of which the spacetime has a deficit angle and study its response to a sc...

We reconsider the thermodynamics of AdS black holes in the context of gauge-gravity duality. In this new setting where both the cosmological constant $\Lambda$ and the gravitational Newton constant $G$ are varied in the bulk, we rewrite the first law in a new form containing both $\Lambda$ (associated with thermodynamic pressure) and the central ch...

A bstract Within the framework of the “complexity equals action” and “complexity equals volume” conjectures, we study the properties of holographic complexity for rotating black holes. We focus on a class of odd-dimensional equal-spinning black holes for which considerable simplification occurs. We study the complexity of formation, uncovering a di...

We study the holographic complexity conjectures for rotating black holes, uncovering a relationship between the complexity of formation and the thermodynamic volume of the black hole. We suggest that it is the thermodynamic volume and not the entropy that controls the complexity of formation of large black holes in both the complexity equals action...

We investigate the sensitivity of an Unruh-DeWitt detector to the global features of a deficit angle that are otherwise classically inaccessible. Specifically, we consider a detector placed inside an infinite thin hollow cylinder whose spacetime is everywhere flat but outside of which the spacetime has a deficit angle and study its response to a sc...

We carry out the first investigation of the entanglement and mutual information harvesting protocols for freely falling trajectories in (1 + 1)-dimensional Schwarzschild black hole spacetime. We consider two pointlike Unruh-DeWitt (UDW) detectors in different combinations of free-falling and static trajectories and compare the results. We show that...

We obtain charged and rotating black hole solutions to the novel 3D Gauss-Bonnet theory of gravity recently proposed, both of which generalize the Banados-Teitelboim-Zanelli (BTZ) metric. The charged solutions are obtained in the Maxwell and Born-Infeld theories and feature 'universal thermodynamics' - identical to the thermodynamics of their Einst...

Understanding the dynamic process of black hole thermodynamic phase transitions at a triple point is a huge challenge. In this letter, we carry out the first investigation of dynamical phase behaviour at a black hole triple point. By numerically solving the Smoluchowski equation near the triple point for a six-dimensional charged Gauss-Bonnet anti-...

A bstract We investigate the thermodynamic properties of 3+1 dimensional black holes in asymptotically de Sitter spacetimes, conformally coupled to a real scalar field. We use a Euclidean action approach, where boundary value data is specified at a finite radius ‘cavity’ outside the black hole, working in the extended phase space where the cosmolog...

A relativistic theory of gravity like general relativity produces phenomena differing fundamentally from Newton’s theory. An example, analogous to electromagnetic induction, is gravitomagnetism, or the dragging of inertial frames by mass-energy currents. These effects have recently been confirmed by classical observations. Here we show, for the fir...

Universal relations and constants have important applications in understanding a physical theory. In this article, we explore this issue for Hawking-Page phase transitions in Schwarzschild anti–de Sitter black holes. We find a novel exact dual relation between the minimum temperature of the (d+1)-dimensional black hole and the Hawking-Page phase tr...

Within the framework of the "complexity equals action" and "complexity equals volume" conjectures, we study the properties of holographic complexity for rotating black holes. We focus on a class of odd-dimensional equal-spinning black holes for which considerable simplification occurs. We study the complexity of formation, uncovering a direct conne...

We construct slowly rotating black-hole solutions of Einsteinian cubic gravity (ECG) in four dimensions with flat and anti–de Sitter asymptotes. At leading order in the rotation parameter, the only modification with respect to the static case is the appearance of a nonvanishing gtϕ component. Similar to the static case, the order of the equation de...

A relativistic theory of gravity like general relativity produces phenomena differing fundamentally from Newton's theory. An example, analogous to electromagnetic induction, is gravitomagnetism, or the dragging of inertial frames by mass-energy currents. These effects have recently been confirmed by classical observations. Here we show, for the fir...

The Unruh effect is a surprising prediction of quantum field theory that asserts accelerating observers perceive a thermal spectrum of particles with a temperature proportional to their acceleration. However, it has recently been shown that particle detectors can click less often or even cool down as their acceleration increases, in contrast to the...

A bstract We study the harvesting of correlations by two Unruh-DeWitt static detectors from the vacuum state of a massless scalar field in a background Vaidya spacetime consisting of a collapsing null shell that forms a Schwarzschild black hole (hereafter Vaidya spacetime for brevity), and we compare the results with those associated with the three...

The nonclassicality of simple spin systems as measured by Wigner negativity is studied on a spherical phase space. Several SU(2)-covariant states with common qubit representations are addressed: spin coherent, spin cat (GHZ/N00N), and Dicke ($\textsf{W}$). We derive a bound on the Wigner negativity of spin cat states that rapidly approaches the tru...

We investigate the thermodynamic properties of 3+1 dimensional black holes in asymptotically de Sitter spacetimes, conformally coupled to a real scalar field. We use a Euclidean action approach, where boundary value data is specified at a finite radius `cavity' outside the black hole, working in the extended phase space where the cosmological const...

We study the harvesting of correlations by two Unruh-DeWitt static detectors from the vacuum state of a massless scalar field in background Vaidya spacetime, and we compare the results with those associated with the three preferred vacua (Boulware, Unruh, Hartle-Hawking-Israel vacua) in Schwarzschild spacetime. To do this we make use of the explici...

A bstract We comment on the recently introduced Gauss-Bonnet gravity in four dimensions. We argue that it does not make sense to consider this theory to be defined by a set of D → 4 solutions of the higher-dimensional Gauss-Bonnet gravity. We show that a well-defined D → 4 limit of Gauss-Bonnet Gravity is obtained generalizing a method employed by...

We consider the D→3 limit of Gauss–Bonnet gravity. We find two distinct but similar versions of the theory and obtain black hole solutions for each. For one theory the solution is an interesting generalization of the BTZ black hole that does not have constant curvature but whose thermodynamics is identical. The other theory admits a solution that i...

Universal relations and constants have important applications in understanding a physical theory. In this letter, we explore this issue for Hawking-Page phase transitions in Schwarzschild anti de Sitter black holes. We find a novel exact dual relation between the minimum temperature of the ($d$+1)-dimensional black hole and the Hawking-Page phase t...

We study the response function of Unruh-deWitt detectors placed in a flat spacetime inside a thin matter shell. We show that the response function distinguishes between the local and global (Minkowski) inertial frames and picks up the presence of the shell even when the detector is switched on for a finite time interval within which a light signal...

We obtain rotating black hole solutions to the novel 3D Gauss-Bonnet theory of gravity recently proposed. These solutions generalize the BTZ metric and are not of constant curvature. They possess an ergoregion and outer horizon, but do not have an inner horizon. We present their basic properties and show that they break the universality of thermody...

We investigate how a static and neutral distribution of external matter distorts a five-dimensional static black ring. We obtain a general expression for the distorted metric in terms of the background metric functions and the distortion fields, and find a multipole expansion for the latter. We demonstrate that the gravitational field of these exte...

We consider the $D\to 3$ limit of Gauss-Bonnet gravity. We find two distinct but similar versions of the theory and obtain black hole solutions for each. For one theory the solution is an interesting generalization of the BTZ black hole that does not have constant curvature but whose thermodynamics is identical. The other theory admits a solution t...

We investigate the thermodynamics of Gauss–Bonnet black holes in asymptotically de Sitter spacetimes embedded in an isothermal cavity, via a Euclidean action approach. We consider both charged and uncharged black holes, working in the extended phase space where the cosmological constant is treated as a thermodynamic pressure. We examine the phase s...

We comment on the recently introduced Gauss-Bonnet gravity in four dimensions. We argue that it does not make sense to consider this theory to be defined by a set of $D\to 4$ solutions of the higher-dimensional Gauss-Bonnet gravity. We show that a well-defined $D\to 4$ limit of Gauss-Bonnet Gravity is obtained generalizing a method employed by Mann...

We construct slowly rotating black-hole solutions of Einsteinian cubic gravity (ECG) in four dimensions with flat and AdS asymptotes. At leading order in the rotation parameter, the only modification with respect to the static case is the appearance of a non-vanishing $g_{t\phi}$ component. Similarly to the static case, the order of the equation de...

An idealized “test” object in general relativity moves along a geodesic. However, if the object has a finite mass, this will create additional curvature in the spacetime, causing it to deviate from geodesic motion. If the mass is nonetheless sufficiently small, such an effect is usually treated perturbatively and is known as the gravitational self-...

We study the response function of Unruh-deWitt detectors placed in a flat spacetime inside a thin matter shell. We show that the response function distinguishes between the local and global (Minkowski) inertial frames and picks up the presence of the shell even when the detector is switched on for a finite time interval within which a light signal...

We investigate how a static and neutral distribution of external matter distorts a 5-dimensional static black ring. We obtain a general expression for the distorted metric in terms of the background metric functions and the distortion fields, and find a multipole expansion for the latter. We demonstrate that the gravitational field of these externa...

We investigate the thermodynamics of Gauss-Bonnet black holes in asymptotically de Sitter spacetimes embedded in an isothermal cavity, via a Euclidean action approach. We consider both charged an uncharged black holes, working in the extended phase space where the cosmological constant is treated as a thermodynamic pressure. We examine the phase st...