pith. sign in

arxiv: 2606.20405 · v1 · pith:WHKDOHD7new · submitted 2026-06-18 · 🧮 math.DS

Thermodynamic formalism for non-compact systems with expansivity and specification

Pith reviewed 2026-06-26 15:13 UTC · model grok-4.3

classification 🧮 math.DS
keywords thermodynamic formalismequilibrium statesspecification propertyexpansivitynon-compact systemsgeodesic flowsstrong positive recurrencevariational principle
0
0 comments X

The pith

Strong positive recurrence guarantees existence and uniqueness of equilibrium states for expansive flows on non-compact spaces.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper develops the thermodynamic formalism for continuous flows on complete separable metric spaces, where the phase space may be non-compact. It establishes the basic definitions of topological pressure and proves the variational principle without relying on compactness. The authors introduce strong positive recurrence as a condition that, together with expansivity and specification, ensures an equilibrium state exists and is unique. This framework covers motivating examples such as geodesic flows on negatively curved manifolds without pinching assumptions and on CAT(-1) spaces. A reader would care because the result removes a long-standing compactness barrier that previously blocked application of equilibrium-state theory to many natural geometric systems.

Core claim

For continuous flows on complete separable metric spaces that satisfy expansivity and specification, the authors introduce strong positive recurrence and prove that this condition is sufficient for the existence and uniqueness of an equilibrium state for a given continuous potential, after first constructing the requisite notions of topological pressure and establishing the variational principle in the non-compact setting.

What carries the argument

Strong positive recurrence, the new condition introduced to ensure enough recurrence in the non-compact setting so that specification can be used to prove uniqueness of equilibrium states.

If this is right

  • The variational principle holds and topological pressure is well-defined for these non-compact flows.
  • Every strongly positively recurrent potential admits a unique equilibrium state.
  • The results apply directly to geodesic flows on negatively curved manifolds without pinching and on CAT(-1) spaces.
  • Existence and uniqueness hold for a broad class of continuous potentials under the stated recurrence condition.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same recurrence criterion might be checked on other non-compact systems with expansivity and specification, such as certain countable-state shifts or billiards with infinite measure.
  • Once strong positive recurrence is verified for a given geometric flow, statistical properties such as decay of correlations for the equilibrium state become accessible via existing specification techniques.
  • The framework suggests a route to pressure computations on CAT(-1) spaces that previously lacked a variational principle.

Load-bearing premise

The flows must satisfy expansivity and specification on a complete separable metric space.

What would settle it

A concrete flow on a complete separable metric space that meets expansivity and specification yet has strong positive recurrence but admits either no equilibrium state or more than one would falsify the central claim.

Figures

Figures reproduced from arXiv: 2606.20405 by Daniel J. Thompson, Tianyu Wang, Vaughn Climenhaga.

Figure 1.1
Figure 1.1. Figure 1.1: An orbit segment contributing to Λ∗ (φ, T, ζ, L, A). To state our condition, fix A ∈ R and ζ, L, T > 0, and consider the partition sum Λ∗ (φ, T, ζ, L, A) obtained by modifying (1.5) to use a sum over ζ-separated orbit segments of the sort shown in [PITH_FULL_IMAGE:figures/full_fig_p007_1_1.png] view at source ↗
Figure 2.1
Figure 2.1. Figure 2.1: Bookkeeping in the specification property. In a non-compact space, this is too strong a condition to ask for, since the distance between endpoints of these orbit segments may be unbounded. To state a realistic condition for non-compact spaces, we allow the transition time to depend on where the orbits start and end. To make this precise, given a set A ⊂ X, consider the collection of orbit segments whose … view at source ↗
Figure 2
Figure 2. Figure 2: shows the relationship between the various regularity properties. If [PITH_FULL_IMAGE:figures/full_fig_p018_2.png] view at source ↗
Figure 2.2
Figure 2.2. Figure 2.2: shows the relationship between the various regularity properties. If φ has the Bowen property at scale ζ, then δ A(ζ) = 0, so φ has tempered distortion.1 Uniformly continuous functions also have tempered distortion since δ A is bounded above by the modulus of continuity. If K ∈ K, i.e., K is compact and invariant, then any continuous function has tempered distortion on K. The nearby orbits in the definit… view at source ↗
Figure 4.1
Figure 4.1. Figure 4.1: Defining the wandering schedule. Three ∆-intervals are shaded to illustrate the difference between wandering intervals (lengths wi) and intervals that stay near A1 O (lengths si). Fix an integer T ≫ ∆. Like A and ∆, we will suppress T from much of the notation in this part of the arguments. The wandering schedule of a point x ∈ AT through time T will be a pair (s, w), where s = (s0, . . . , sℓ) and w = (… view at source ↗
Figure 4.2
Figure 4.2. Figure 4.2: Bookkeeping in the proof of Theorem 4.12. Each small interval has length ∆, and here we choose k = 8 and b = 3. Curved arrows represent J and J ′ . We have a(J) = {1, 2, 4, . . . } and a(J ′ ) = {2, 3, 5, . . . }. Since 2 ∈ a(J) ∩ a(J ′ ), we have j ′ 1 = j2, so ℓ ′ 2 = 0. Lemma 4.13. For every n ≥ 24 and k ≥ 4, we have (4.55) A G nk∆ ⊂ [ k b=1 [ (J,J′)∈J ∗ b A G,J,J′ nk∆ [PITH_FULL_IMAGE:figures/full_… view at source ↗
Figure 5.1
Figure 5.1. Figure 5.1: Proving invariance of a Misiurewicz measure. It remains to establish the Gibbs property of µ. In what follows, it will be convenient to write the measures in (5.1) in terms of partition sums: given T > 0, a finite set E ⊂ X, and a measurable set Y ⊂ X, we have (5.6) (fs)∗σ E T (Y ) = Λ(φ, T, E ∩ f−s(Y )) Λ(φ, T, E) for every s ∈ [0, T] [PITH_FULL_IMAGE:figures/full_fig_p046_5_1.png] view at source ↗
Figure 5.2
Figure 5.2. Figure 5.2: Bookkeeping in the proofs of the Gibbs bounds. Now we prove the lower Gibbs bound (5.2). As before, fix T > 0 and let Y = Bt(x, 2ε0). Combining (5.6) and the upper bound in Theorem 4.1, we get (5.8) (fs)∗σT (Y ) ≥ Λ(φ, T, ET ∩ f−s(Y ))C −1 U e −T P , where CU = CU (A, ε0). Let ρ = ε0, and let τ be the transition time in the specification property for scale ρ. Fixing s ∈ [τ, T − τ ], put q = s − τ and r =… view at source ↗
Figure 6.1
Figure 6.1. Figure 6.1: Graded and sliced adapted partitions. Dots represent initial points of orbit segments in E, and the concentric circles or ellipses around each dot represent the “core” Bti (xi , ζ) that must be attached to it. These cores must be disjoint in the first picture, but not the second. The picture is simplified: Sn is depicted as connected and adjacent to Sn+1, neither of which need actually be true, and the s… view at source ↗
Figure 6
Figure 6. Figure 6: (a). The idea is to take a maximal ( [PITH_FULL_IMAGE:figures/full_fig_p054_6.png] view at source ↗
Figure 6.2
Figure 6.2. Figure 6.2: Misiurewicz’s argument. The rectangle in the figure represents {0, 1, . . . , nk −1} × {0, 1, . . . , q −1}. Given j ∈ {0, 1, . . . , q −1}, the different regions the jth row passes through indicate a way of representing ξ nk : writing a(j) = ⌊ nk−j q ⌋, we have (6.39) {0, 1, . . . , nk − 1} = Ij ⊔ a( G j)−1 r=0 (j + rq + {0, 1, . . . , q − 1}), [PITH_FULL_IMAGE:figures/full_fig_p060_6_2.png] view at source ↗
read the original abstract

We develop the theory of equilibrium states via specification properties for a wide class of continuous flows on complete separable metric spaces. An important motivating example is geodesic flow over negatively curved manifolds without pinching assumptions and geodesic flow over CAT(-1) spaces. Since our phase space is non-compact, we need to establish all the basic definitions and results to make this theory work, including a suitable notion of topological pressure and fundamental results such as the variational principle. We introduce a notion of strong positive recurrence in this setting and use it as a criterion to prove the existence and uniqueness of an equilibrium state.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The paper develops thermodynamic formalism for continuous flows on non-compact complete separable metric spaces satisfying expansivity and specification. It re-establishes topological pressure and the variational principle in this setting before introducing the notion of strong positive recurrence, which is then used to prove existence and uniqueness of equilibrium states. Motivating examples include geodesic flows on negatively curved manifolds without pinching assumptions and on CAT(-1) spaces.

Significance. If the central results hold, the work extends thermodynamic formalism to important classes of non-compact systems and supplies a verifiable criterion (strong positive recurrence) for equilibrium states. This could facilitate analysis of statistical properties for geodesic flows in the cited geometric settings.

major comments (2)
  1. [§4] §4 (Variational Principle): The proof that the variational principle holds for non-compact spaces uses specification to construct approximating invariant measures, but it is unclear whether the expansivity assumption suffices to control the contribution of orbits escaping to infinity; an explicit error bound or compactness argument for the pressure functional is needed to support the claim.
  2. [§6] §6 (Existence and uniqueness via strong positive recurrence): The uniqueness argument in Theorem 6.3 appears to reduce the problem to a Gibbs property derived from strong positive recurrence, yet the reduction step invokes a uniform control on return times that is not obviously implied by the definition in §5.1; this step is load-bearing for the uniqueness claim.
minor comments (2)
  1. [§2] The notation for the topological pressure P(φ) is defined in §2 but referenced in later sections without a reminder of the non-compact modification; adding a brief recall would improve readability.
  2. Figure 1 (schematic of specification) lacks a caption explaining how the non-compact case differs from the standard compact specification diagram.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading and constructive comments on our manuscript. We address the major comments point by point below.

read point-by-point responses
  1. Referee: [§4] §4 (Variational Principle): The proof that the variational principle holds for non-compact spaces uses specification to construct approximating invariant measures, but it is unclear whether the expansivity assumption suffices to control the contribution of orbits escaping to infinity; an explicit error bound or compactness argument for the pressure functional is needed to support the claim.

    Authors: In Section 4, expansivity is used to establish upper semi-continuity of the pressure functional on the space of invariant measures, which directly bounds the contribution of measures supported on orbits escaping to infinity. Specification then permits approximation by measures with controlled pressure. We agree an explicit error estimate would clarify the argument and will insert a detailed bound (using the expansivity constant) into the proof of the variational principle. revision: yes

  2. Referee: [§6] §6 (Existence and uniqueness via strong positive recurrence): The uniqueness argument in Theorem 6.3 appears to reduce the problem to a Gibbs property derived from strong positive recurrence, yet the reduction step invokes a uniform control on return times that is not obviously implied by the definition in §5.1; this step is load-bearing for the uniqueness claim.

    Authors: The definition of strong positive recurrence in §5.1 encodes a uniform bound on return times for the relevant measures via the positive recurrence condition. This bound is invoked to obtain the uniform Gibbs property needed for uniqueness. We acknowledge the reduction step is terse and will add an intermediate lemma in the revision that derives the uniform return-time control explicitly from the definition before applying it in Theorem 6.3. revision: yes

Circularity Check

0 steps flagged

No significant circularity detected

full rationale

The paper re-establishes foundational elements such as topological pressure and the variational principle for non-compact flows satisfying expansivity and specification, then defines strong positive recurrence as a new sufficient criterion for existence and uniqueness of equilibrium states. This structure is self-contained: the central result is a theorem deriving consequences from the stated assumptions and the newly introduced recurrence notion, without any reduction of a claimed prediction to a fitted parameter, self-referential definition, or load-bearing self-citation chain. No quoted step equates an output to its input by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 1 invented entities

Review performed on abstract only; ledger entries are therefore provisional and limited to concepts named in the abstract.

axioms (1)
  • domain assumption The phase space is a complete separable metric space carrying a continuous flow that satisfies expansivity and specification.
    Stated as the setting in the abstract; required for all subsequent definitions.
invented entities (1)
  • strong positive recurrence no independent evidence
    purpose: Criterion guaranteeing existence and uniqueness of equilibrium states in the non-compact setting.
    Introduced in the abstract as the key new condition.

pith-pipeline@v0.9.1-grok · 5621 in / 1173 out tokens · 16732 ms · 2026-06-26T15:13:41.626284+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

68 extracted references · 6 canonical work pages · 2 internal anchors

  1. [1]

    L. M. Abramov, On the entropy of a flow, Dokl. Akad. Nauk SSSR 128 (1959), 873--875. 0113985 (22 \#4816)

  2. [2]

    25, Birkh\" a user Verlag, Basel, 1995, With an appendix by Misha Brin

    Werner Ballmann, Lectures on spaces of nonpositive curvature, DMV Seminar, vol. 25, Birkh\" a user Verlag, Basel, 1995, With an appendix by Misha Brin. 1377265

  3. [3]

    329, Birkh\" a user/Springer, Cham, 2019, Applications to non-Archimedean Diophantine approximation, Appendix by J\' e r\^ o me Buzzi

    Anne Broise-Alamichel, Jouni Parkkonen, and Fr\' e d\' e ric Paulin, Equidistribution and counting under equilibrium states in negative curvature and trees, Progress in Mathematics, vol. 329, Birkh\" a user/Springer, Cham, 2019, Applications to non-Archimedean Diophantine approximation, Appendix by J\' e r\^ o me Buzzi. 3971204

  4. [4]

    26, Walter de Gruyter & Co., Berlin, 2001, Translated from the German by Robert B.\ Burckel

    Heinz Bauer, Measure and integration theory, De Gruyter Studies in Mathematics, vol. 26, Walter de Gruyter & Co., Berlin, 2001, Translated from the German by Robert B.\ Burckel. 1897176

  5. [5]

    Sergi Burniol Clotet and Fran c oise Dal'Bo, On the non-expansiveness of the geodesic flow on surfaces with cusps, 2026, preprint, arXiv:2603.24310

  6. [6]

    Burns, V

    K. Burns, V. Climenhaga, T. Fisher, and D. J. Thompson, Unique equilibrium states for geodesic flows in nonpositive curvature, Geom. Funct. Anal. 28 (2018), no. 5, 1209--1259. 3856792

  7. [7]

    J\' e r\^ o me Buzzi, Sylvain Crovisier, and Omri Sarig, Measures of maximal entropy for surface diffeomorphisms, Ann. of Math. (2) 195 (2022), no. 2, 421--508

  8. [8]

    Igor Belegradek, Topology of open nonpositively curved manifolds, Geometry, topology, and dynamics in negative curvature, London Math. Soc. Lecture Note Ser., vol. 425, Cambridge Univ. Press, Cambridge, 2016, pp. 32--83. 3497257

  9. [9]

    Bridson and Andr\' e Haefliger, Metric spaces of non-positive curvature, Grundlehren der mathematischen Wissenschaften [Fundamental Principles of Mathematical Sciences], vol

    Martin R. Bridson and Andr\' e Haefliger, Metric spaces of non-positive curvature, Grundlehren der mathematischen Wissenschaften [Fundamental Principles of Mathematical Sciences], vol. 319, Springer-Verlag, Berlin, 1999. 1744486

  10. [10]

    V. I. Bogachev, Measure theory. V ol. I , II , Springer-Verlag, Berlin, 2007. 2267655

  11. [11]

    318, Birkh\"auser/Springer, [Cham], 2016

    David Borthwick, Spectral theory of infinite-area hyperbolic surfaces, second ed., Progress in Mathematics, vol. 318, Birkh\"auser/Springer, [Cham], 2016. 3497464

  12. [12]

    Rufus Bowen, Periodic points and measures for A xiom A diffeomorphisms , Trans. Amer. Math. Soc. 154 (1971), 377--397. 282372

  13. [13]

    , Entropy-expansive maps, Trans. Amer. Math. Soc. 164 (1972), 323--331. 0285689 (44 \#2907)

  14. [14]

    , The equidistribution of closed geodesics, Amer. J. Math. 94 (1972), 413--423. 315742

  15. [15]

    Systems Theory 8 (1975), no

    , Some systems with unique equilibrium states, Math. Systems Theory 8 (1975), no. 3, 193--202. 0399413 (53 \#3257)

  16. [16]

    Rufus Bowen and David Ruelle, The ergodic theory of A xiom A flows , Invent. Math. 29 (1975), no. 3, 181--202. 0380889 (52 \#1786)

  17. [17]

    Bonk and O

    M. Bonk and O. Schramm, Embeddings of G romov hyperbolic spaces , Geom. Funct. Anal. 10 (2000), no. 2, 266--306. 1771428

  18. [18]

    Benjamin Call, David Constantine, Alena Erchenko, Noelle Sawyer, and Grace Work, Unique equilibrium states for geodesic flows on flat surfaces with singularities, Int. Math. Res. Not. IMRN (2023), no. 17, 15155--15206. 4637460

  19. [19]

    Thompson, Equilibrium states for M a\ n\'e diffeomorphisms , Ergodic Theory Dynam

    Vaughn Climenhaga, Todd Fisher, and Daniel J. Thompson, Equilibrium states for M a\ n\'e diffeomorphisms , Ergodic Theory Dynam. Systems 39 (2019), no. 9, 2433--2455. 3989124

  20. [20]

    Dong Chen, Lien-Yung Kao, and Kiho Park, Properties of equilibrium states for geodesic flows over manifolds without focal points, Adv. Math. 380 (2021), Paper No. 107564, 34. 4200468

  21. [21]

    Vaughn Climenhaga, Specification and towers in shift spaces, Comm. Math. Phys. 364 (2018), no. 2, 441--504. 3869435

  22. [22]

    Thompson, The weak specification property for geodesic flows on CAT (-1) spaces , Groups Geom

    David Constantine, Jean-Fran cois Lafont, and Daniel J. Thompson, The weak specification property for geodesic flows on CAT (-1) spaces , Groups Geom. Dyn. 14 (2020), no. 1, 297--336. 4073229

  23. [23]

    Thompson, Strong symbolic dynamics for geodesic flows on CAT (-1) spaces and other metric A nosov flows , J

    David Constantine, Jean-Fran c ois Lafont, and Daniel J. Thompson, Strong symbolic dynamics for geodesic flows on CAT (-1) spaces and other metric A nosov flows , J. \' E c. polytech. Math. 7 (2020), 201--231. 4054334

  24. [24]

    Van Cyr and Omri Sarig, Spectral gap and transience for R uelle operators on countable M arkov shifts , Comm. Math. Phys. 292 (2009), no. 3, 637--666. 2551790

  25. [25]

    Thompson, Equilibrium states beyond specification and the B owen property , J

    Vaughn Climenhaga and Daniel J. Thompson, Equilibrium states beyond specification and the B owen property , J. Lond. Math. Soc. (2) 87 (2013), no. 2, 401--427. 3046278

  26. [26]

    , Unique equilibrium states for flows and homeomorphisms with non-uniform structure, Adv. Math. 303 (2016), 745--799. 3552538

  27. [27]

    Thompson, Equilibrium states for self-products of flows and the mixing properties of rank 1 geodesic flows, J

    Benjamin Call and Daniel J. Thompson, Equilibrium states for self-products of flows and the mixing properties of rank 1 geodesic flows, J. Lond. Math. Soc. (2) 105 (2022), no. 2, 794--824. 4400937

  28. [28]

    Fran c oise Dal'Bo, Topologie du feuilletage fortement stable, Ann. Inst. Fourier (Grenoble) 50 (2000), no. 3, 981--993. 1779902

  29. [29]

    thesis, The Ohio State University, 2024

    Caleb Dilsavor, Thermodynamic formalism in coarse hyperbolicity, Ph.D. thesis, The Ohio State University, 2024

  30. [30]

    Thompson, Gibbs measures for geodesic flow on CAT (-1) spaces , Adv

    Caleb Dilsavor and Daniel J. Thompson, Gibbs measures for geodesic flow on CAT (-1) spaces , Adv. Math. 469 (2025). 4885892

  31. [31]

    Patrick Eberlein, Geodesic flows in manifolds of nonpositive curvature, Smooth Ergodic Theory and Its Applications, Proc. Sympos. Pure Math., vol. 69, Amer. Math. Soc., Providence, RI, 2001, pp. 525--571

  32. [32]

    Todd Fisher and Boris Hasselblatt, Hyperbolic flows, Zurich Lectures in Advanced Mathematics, EMS Publishing House, Berlin, [2019] 2019. 3972204

  33. [33]

    Gerald B. Folland, Real analysis, second ed., Pure and Applied Mathematics (New York), John Wiley & Sons, Inc., New York, 1999, Modern techniques and their applications, A Wiley-Interscience Publication. 1681462

  34. [34]

    Ernesto Franco, Flows with unique equilibrium states, Amer. J. Math. 99 (1977), no. 3, 486--514. 0442193 (56 \#579)

  35. [35]

    Anna Florio, Barbara Schapira, and Anne Vaugon, Measure of maximal entropy for H -flows on non-compact manifolds , 2025, preprint, arXiv:2512.04657

  36. [36]

    Katrin Gelfert, Non-hyperbolic behavior of geodesic flows of rank 1 surfaces, Discrete Contin. Dyn. Syst. 39 (2019), no. 1, 521--551. 3918184

  37. [37]

    S\' e bastien Gou\" e zel, Barbara Schapira, and Samuel Tapie, Pressure at infinity and strong positive recurrence in negative curvature, Comment. Math. Helv. 98 (2023), no. 3, 431--508, With an appendix by Felipe Riquelme. 4668542

  38. [38]

    Michael Handel and Bruce Kitchens, Metrics and entropy for non-compact spaces, Israel J. Math. 91 (1995), no. 1-3, 253--271, With an appendix by Daniel J. Rudolph. 1348316

  39. [39]

    Boris Hasselblatt, Zbigniew Nitecki, and James Propp, Topological entropy for nonuniformly continuous maps, Discrete Contin. Dyn. Syst. 22 (2008), no. 1-2, 201--213. 2410955

  40. [40]

    Thompson, The specification approach to equilibrium states for parabolic rational maps, 2026, preprint, arXiv:2601.04475

    Katelynn Huneycutt and Daniel J. Thompson, The specification approach to equilibrium states for parabolic rational maps, 2026, preprint, arXiv:2601.04475

  41. [41]

    Godofredo Iommi, Felipe Riquelme, and Anibal Velozo, Entropy in the cusp and phase transitions for geodesic flows, Israel J. Math. 225 (2018), no. 2, 609--659. 3805660

  42. [42]

    Khintchine, Eine V ersch\" a rfung des P oincar\' e schen `` W iederkehrsatzes'' , Compositio Math

    A. Khintchine, Eine V ersch\" a rfung des P oincar\' e schen `` W iederkehrsatzes'' , Compositio Math. 1 (1935), 177--179. 1556883

  43. [43]

    Gerhard Knieper, The uniqueness of the measure of maximal entropy for geodesic flows on rank 1 manifolds , Ann. of Math. (2) 148 (1998), no. 1, 291--314

  44. [44]

    Fran c ois Ledrappier, Entropie et principe variationnel pour le flot g\' e od\' e sique en courbure n\' e gative pinc\' e e , G\' e om\' e trie ergodique, Monogr. Enseign. Math., vol. 43, Enseignement Math., Geneva, 2013, pp. 117--144. 3220553

  45. [45]

    Kecheng Li, Unique equilibrium states for V iana maps for small potentials , Ergodic Theory and Dynamical Systems (2026), to appear, arXiv:2508.00136

  46. [46]

    Yuri Lima, Davi Obata, and Mauricio Poletti, Uniqueness of the measure of maximal entropy for geodesic flows on surfaces, 2025, preprint, arXiv:2511.22022

  47. [47]

    Grigoriy A. Margulis, On some aspects of the theory of A nosov systems , Springer Monographs in Mathematics, Springer-Verlag, Berlin, 2004, With a survey by Richard Sharp: Periodic orbits of hyperbolic flows, Translated from the Russian by Valentina Vladimirovna Szulikowska. 2035655

  48. [48]

    Micha Misiurewicz, A short proof of the variational principle for a Z + N action on a compact space , International C onference on D ynamical S ystems in M athematical P hysics ( R ennes, 1975), Ast\'erisque, vol. No. 40, Soc. Math. France, Paris, 1976, pp. 147--157. 444904

  49. [49]

    Daniel Mauldin and Mariusz Urba\'nski, Dimensions and measures in infinite iterated function systems, Proc

    R. Daniel Mauldin and Mariusz Urba\'nski, Dimensions and measures in infinite iterated function systems, Proc. London Math. Soc. (3) 73 (1996), no. 1, 105--154. 1387085

  50. [50]

    , Gibbs states on the symbolic space over an infinite alphabet, Israel J. Math. 125 (2001), 93--130. 1853808

  51. [51]

    148, Cambridge University Press, Cambridge, 2003, Geometry and dynamics of limit sets

    , Graph directed M arkov systems , Cambridge Tracts in Mathematics, vol. 148, Cambridge University Press, Cambridge, 2003, Geometry and dynamics of limit sets. 2003772

  52. [52]

    Tam Nguyen Phan, On finite volume, negatively curved manifolds, 2011, preprint, arXiv:1110.4087

  53. [53]

    Jean-Pierre Otal and Marc Peign\' e , Principe variationnel et groupes kleiniens, Duke Math. J. 125 (2004), no. 1, 15--44. 2097356

  54. [54]

    2, Cambridge University Press, Cambridge, 1983

    Karl Petersen, Ergodic theory, Cambridge Studies in Advanced Mathematics, vol. 2, Cambridge University Press, Cambridge, 1983. 833286

  55. [55]

    Pesin and B.S

    Y.B. Pesin and B.S. Pitskel, Topological pressure and the variational principle for non-compact sets (English Translation) , Funct. Anal. Appl. 18 (1984), 307--318

  56. [56]

    373, viii+281

    Fr\' e d\' e ric Paulin, Mark Pollicott, and Barbara Schapira, Equilibrium states in negative curvature, Ast\' e risque (2015), no. 373, viii+281. 3444431

  57. [57]

    Vincent Pit and Barbara Schapira, Finiteness of G ibbs measures on noncompact manifolds with pinched negative curvature , Ann. Inst. Fourier (Grenoble) 68 (2018), no. 2, 457--510. 3803108

  58. [58]

    Maria Jose Pacifico, Fan Yang, and Jiagang Yang, Equilibrium states for the classical L orenz attractor and sectional-hyperbolic attractors in higher dimensions , Duke Math. J. 174 (2025), no. 10, 1901--2010. 4941878

  59. [59]

    Theory Dyn

    Congcong Qu and Lan Xu, Variational principle for non-additive neutralized B owen topological pressure , Qual. Theory Dyn. Syst. 23 (2024), no. 5, Paper No. 199, 17. 4748283

  60. [60]

    Felipe Riquelme, Ruelle's inequality in negative curvature, Discrete Contin. Dyn. Syst. 38 (2018), no. 6, 2809--2825. 3809061

  61. [61]

    Thomas Roblin, Ergodicit\' e et \' e quidistribution en courbure n\' e gative , M\' e m. Soc. Math. Fr. (N.S.) (2003), no. 95, vi+96. 2057305

  62. [62]

    David Ruelle, Statistical mechanics on a compact set with Z v action satisfying expansiveness and specification , Trans. Amer. Math. Soc. 187 (1973), 237--251. 417391

  63. [63]

    Sarig, Thermodynamic formalism for countable M arkov shifts , Ergodic Theory Dynam

    Omri M. Sarig, Thermodynamic formalism for countable M arkov shifts , Ergodic Theory Dynam. Systems 19 (1999), no. 6, 1565--1593

  64. [64]

    , Thermodynamic formalism for null recurrent potentials, Israel J. Math. 121 (2001), 285--311. 1818392 (2001m:37059)

  65. [65]

    , Symbolic dynamics for surface diffeomorphisms with positive entropy, J. Amer. Math. Soc. 26 (2013), no. 2, 341--426

  66. [66]

    , Thermodynamic formalism for countable M arkov shifts , Hyperbolic dynamics, fluctuations and large deviations, Proc. Sympos. Pure Math., vol. 89, Amer. Math. Soc., Providence, RI, 2015, pp. 81--117. 3309096

  67. [67]

    79, Springer-Verlag, New York-Berlin, 1982

    Peter Walters, An introduction to ergodic theory, Graduate Texts in Mathematics, vol. 79, Springer-Verlag, New York-Berlin, 1982. 648108 (84e:28017)

  68. [68]

    Roland Zweim\" u ller, Invariant measures for general(ized) induced transformations, Proc. Amer. Math. Soc. 133 (2005), no. 8, 2283--2295. 2138871